Граф коммитов

20679 Коммитов

Автор SHA1 Сообщение Дата
Helge Deller 3033cd4307 parisc: Use generic mmap top-down layout and brk randomization
parisc uses a top-down layout by default that exactly fits the generic
functions, so get rid of arch specific code and use the generic version
by selecting ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT.

Note that on parisc the stack always grows up and a "unlimited stack"
simply means that the value as defined in CONFIG_STACK_MAX_DEFAULT_SIZE_MB
should be used. So RLIM_INFINITY is not an indicator to use the legacy
memory layout.

Signed-off-by: Helge Deller <deller@gmx.de>
2023-08-22 10:24:46 +02:00
Linus Torvalds 190bf7b14b 14 hotfixes. 11 of these are cc:stable and the remainder address post-6.4
issues, or are not considered suitable for -stable backporting.
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Merge tag 'mm-hotfixes-stable-2023-08-11-13-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "14 hotfixes. 11 of these are cc:stable and the remainder address
  post-6.4 issues, or are not considered suitable for -stable
  backporting"

* tag 'mm-hotfixes-stable-2023-08-11-13-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/damon/core: initialize damo_filter->list from damos_new_filter()
  nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput
  selftests: cgroup: fix test_kmem_basic false positives
  fs/proc/kcore: reinstate bounce buffer for KCORE_TEXT regions
  MAINTAINERS: add maple tree mailing list
  mm: compaction: fix endless looping over same migrate block
  selftests: mm: ksm: fix incorrect evaluation of parameter
  hugetlb: do not clear hugetlb dtor until allocating vmemmap
  mm: memory-failure: avoid false hwpoison page mapped error info
  mm: memory-failure: fix potential unexpected return value from unpoison_memory()
  mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page
  radix tree test suite: fix incorrect allocation size for pthreads
  crypto, cifs: fix error handling in extract_iter_to_sg()
  zsmalloc: fix races between modifications of fullness and isolated
2023-08-11 14:19:20 -07:00
Kirill A. Shutemov 2288397324 mm: Fix access_remote_vm() regression on tagged addresses
GDB uses /proc/PID/mem to access memory of the target process. GDB
doesn't untag addresses manually, but relies on kernel to do the right
thing.

mem_rw() of procfs uses access_remote_vm() to get data from the target
process. It worked fine until recent changes in __access_remote_vm()
that now checks if there's VMA at target address using raw address.

Untag the address before looking up the VMA.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Christina Schimpe <christina.schimpe@intel.com>
Fixes: eee9c708cc ("gup: avoid stack expansion warning for known-good case")
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-08-09 08:05:23 -07:00
SeongJae Park 5f1fc67f2c mm/damon/core: initialize damo_filter->list from damos_new_filter()
damos_new_filter() is not initializing the list field of newly allocated
filter object.  However, DAMON sysfs interface and DAMON_RECLAIM are not
initializing it after calling damos_new_filter().  As a result, accessing
uninitialized memory is possible.  Actually, adding multiple DAMOS filters
via DAMON sysfs interface caused NULL pointer dereferencing.  Initialize
the field just after the allocation from damos_new_filter().

Link: https://lkml.kernel.org/r/20230729203733.38949-2-sj@kernel.org
Fixes: 98def236f6 ("mm/damon/core: implement damos filter")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:43 -07:00
Johannes Weiner 493614da0d mm: compaction: fix endless looping over same migrate block
During stress testing, the following situation was observed:

     70 root      39  19       0      0      0 R 100.0   0.0 959:29.92 khugepaged
 310936 root      20   0   84416  25620    512 R  99.7   1.5 642:37.22 hugealloc

Tracing shows isolate_migratepages_block() endlessly looping over the
first block in the DMA zone:

       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA      order=9 ret=no_suitable_page
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA      order=9 ret=no_suitable_page
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA      order=9 ret=no_suitable_page
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_finished: node=0 zone=DMA      order=9 ret=no_suitable_page
       hugealloc-310936  [001] ..... 237297.415718: mm_compaction_isolate_migratepages: range=(0x1 ~ 0x400) nr_scanned=513 nr_taken=0

The problem is that the functions tries to test and set the skip bit once
on the block, to avoid skipping on its own skip-set, using
pageblock_aligned() on the pfn as a test.  But because this is the DMA
zone which starts at pfn 1, this is never true for the first block, and
the skip bit isn't set or tested at all.  As a result,
fast_find_migrateblock() returns the same pageblock over and over.

If the pfn isn't pageblock-aligned, also check if it's the start of the
zone to ensure test-and-set-exactly-once on unaligned ranges.

Thanks to Vlastimil Babka for the help in debugging this.

Link: https://lkml.kernel.org/r/20230731172450.1632195-1-hannes@cmpxchg.org
Fixes: 90ed667c03 ("Revert "Revert "mm/compaction: fix set skip in fast_find_migrateblock""")
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:42 -07:00
Mike Kravetz 32c877191e hugetlb: do not clear hugetlb dtor until allocating vmemmap
Patch series "Fix hugetlb free path race with memory errors".

In the discussion of Jiaqi Yan's series "Improve hugetlbfs read on
HWPOISON hugepages" the race window was discovered. 
https://lore.kernel.org/linux-mm/20230616233447.GB7371@monkey/

Freeing a hugetlb page back to low level memory allocators is performed
in two steps.
1) Under hugetlb lock, remove page from hugetlb lists and clear destructor
2) Outside lock, allocate vmemmap if necessary and call low level free
Between these two steps, the hugetlb page will appear as a normal
compound page.  However, vmemmap for tail pages could be missing.
If a memory error occurs at this time, we could try to update page
flags non-existant page structs.

A much more detailed description is in the first patch.

The first patch addresses the race window.  However, it adds a
hugetlb_lock lock/unlock cycle to every vmemmap optimized hugetlb page
free operation.  This could lead to slowdowns if one is freeing a large
number of hugetlb pages.

The second path optimizes the update_and_free_pages_bulk routine to only
take the lock once in bulk operations.

The second patch is technically not a bug fix, but includes a Fixes tag
and Cc stable to avoid a performance regression.  It can be combined with
the first, but was done separately make reviewing easier.


This patch (of 2):

Freeing a hugetlb page and releasing base pages back to the underlying
allocator such as buddy or cma is performed in two steps:
- remove_hugetlb_folio() is called to remove the folio from hugetlb
  lists, get a ref on the page and remove hugetlb destructor.  This
  all must be done under the hugetlb lock.  After this call, the page
  can be treated as a normal compound page or a collection of base
  size pages.
- update_and_free_hugetlb_folio() is called to allocate vmemmap if
  needed and the free routine of the underlying allocator is called
  on the resulting page.  We can not hold the hugetlb lock here.

One issue with this scheme is that a memory error could occur between
these two steps.  In this case, the memory error handling code treats
the old hugetlb page as a normal compound page or collection of base
pages.  It will then try to SetPageHWPoison(page) on the page with an
error.  If the page with error is a tail page without vmemmap, a write
error will occur when trying to set the flag.

Address this issue by modifying remove_hugetlb_folio() and
update_and_free_hugetlb_folio() such that the hugetlb destructor is not
cleared until after allocating vmemmap.  Since clearing the destructor
requires holding the hugetlb lock, the clearing is done in
remove_hugetlb_folio() if the vmemmap is present.  This saves a
lock/unlock cycle.  Otherwise, destructor is cleared in
update_and_free_hugetlb_folio() after allocating vmemmap.

Note that this will leave hugetlb pages in a state where they are marked
free (by hugetlb specific page flag) and have a ref count.  This is not
a normal state.  The only code that would notice is the memory error
code, and it is set up to retry in such a case.

A subsequent patch will create a routine to do bulk processing of
vmemmap allocation.  This will eliminate a lock/unlock cycle for each
hugetlb page in the case where we are freeing a large number of pages.

Link: https://lkml.kernel.org/r/20230711220942.43706-1-mike.kravetz@oracle.com
Link: https://lkml.kernel.org/r/20230711220942.43706-2-mike.kravetz@oracle.com
Fixes: ad2fa3717b ("mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Tested-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: Jiaqi Yan <jiaqiyan@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:41 -07:00
Miaohe Lin faeb2ff2c1 mm: memory-failure: avoid false hwpoison page mapped error info
folio->_mapcount is overloaded in SLAB, so folio_mapped() has to be done
after folio_test_slab() is checked. Otherwise slab folio might be treated
as a mapped folio leading to false 'Someone maps the hwpoison page' error
info.

Link: https://lkml.kernel.org/r/20230727115643.639741-4-linmiaohe@huawei.com
Fixes: 230ac719c5 ("mm/hwpoison: don't try to unpoison containment-failed pages")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:41 -07:00
Miaohe Lin f29623e4a5 mm: memory-failure: fix potential unexpected return value from unpoison_memory()
If unpoison_memory() fails to clear page hwpoisoned flag, return value ret
is expected to be -EBUSY.  But when get_hwpoison_page() returns 1 and
fails to clear page hwpoisoned flag due to races, return value will be
unexpected 1 leading to users being confused.  And there's a code smell
that the variable "ret" is used not only to save the return value of
unpoison_memory(), but also the return value from get_hwpoison_page(). 
Make a further cleanup by using another auto-variable solely to save the
return value of get_hwpoison_page() as suggested by Naoya.

Link: https://lkml.kernel.org/r/20230727115643.639741-3-linmiaohe@huawei.com
Fixes: bf181c5825 ("mm/hwpoison: fix unpoison_memory()")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:41 -07:00
Miaohe Lin f985fc3220 mm/swapfile: fix wrong swap entry type for hwpoisoned swapcache page
Patch series "A few fixup patches for mm", v2.

This series contains a few fixup patches to fix potential unexpected
return value, fix wrong swap entry type for hwpoisoned swapcache page and
so on.  More details can be found in the respective changelogs.


This patch (of 3):

Hwpoisoned dirty swap cache page is kept in the swap cache and there's
simple interception code in do_swap_page() to catch it.  But when trying
to swapoff, unuse_pte() will wrongly install a general sense of "future
accesses are invalid" swap entry for hwpoisoned swap cache page due to
unaware of such type of page.  The user will receive SIGBUS signal without
expected BUS_MCEERR_AR payload.  BTW, typo 'hwposioned' is fixed.

Link: https://lkml.kernel.org/r/20230727115643.639741-1-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20230727115643.639741-2-linmiaohe@huawei.com
Fixes: 6b970599e8 ("mm: hwpoison: support recovery from ksm_might_need_to_copy()")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:40 -07:00
Andrew Yang 4b5d1e47b6 zsmalloc: fix races between modifications of fullness and isolated
We encountered many kernel exceptions of VM_BUG_ON(zspage->isolated ==
0) in dec_zspage_isolation() and BUG_ON(!pages[1]) in zs_unmap_object()
lately.  This issue only occurs when migration and reclamation occur at
the same time.

With our memory stress test, we can reproduce this issue several times
a day.  We have no idea why no one else encountered this issue.  BTW,
we switched to the new kernel version with this defect a few months
ago.

Since fullness and isolated share the same unsigned int, modifications of
them should be protected by the same lock.

[andrew.yang@mediatek.com: move comment]
  Link: https://lkml.kernel.org/r/20230727062910.6337-1-andrew.yang@mediatek.com
Link: https://lkml.kernel.org/r/20230721063705.11455-1-andrew.yang@mediatek.com
Fixes: c4549b8711 ("zsmalloc: remove zspage isolation for migration")
Signed-off-by: Andrew Yang <andrew.yang@mediatek.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-04 13:03:40 -07:00
Linus Torvalds 122e7943b2 11 hotfixes. Five are cc:stable and the remainder address post-6.4 issues
or aren't considered serious enough to justify backporting.
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Merge tag 'mm-hotfixes-stable-2023-07-28-15-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull hotfixes from Andrew Morton:
 "11 hotfixes. Five are cc:stable and the remainder address post-6.4
  issues or aren't considered serious enough to justify backporting"

* tag 'mm-hotfixes-stable-2023-07-28-15-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  mm/memory-failure: fix hardware poison check in unpoison_memory()
  proc/vmcore: fix signedness bug in read_from_oldmem()
  mailmap: update remaining active codeaurora.org email addresses
  mm: lock VMA in dup_anon_vma() before setting ->anon_vma
  mm: fix memory ordering for mm_lock_seq and vm_lock_seq
  scripts/spelling.txt: remove 'thead' as a typo
  mm/pagewalk: fix EFI_PGT_DUMP of espfix area
  shmem: minor fixes to splice-read implementation
  tmpfs: fix Documentation of noswap and huge mount options
  Revert "um: Use swap() to make code cleaner"
  mm/damon/core-test: initialise context before test in damon_test_set_attrs()
2023-07-28 17:19:52 -07:00
Mike Rapoport (IBM) c442a957b2 Revert "mm,memblock: reset memblock.reserved to system init state to prevent UAF"
This reverts commit 9e46e4dcd9.

kbuild reports a warning in memblock_remove_region() because of a false
positive caused by partial reset of the memblock state.

Doing the full reset will remove the false positives, but will allow
late use of memblock_free() to go unnoticed, so it is better to revert
the offending commit.

   WARNING: CPU: 0 PID: 1 at mm/memblock.c:352 memblock_remove_region (kbuild/src/x86_64/mm/memblock.c:352 (discriminator 1))
   Modules linked in:
   CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.5.0-rc3-00001-g9e46e4dcd9d6 #2
   RIP: 0010:memblock_remove_region (kbuild/src/x86_64/mm/memblock.c:352 (discriminator 1))
   Call Trace:
     memblock_discard (kbuild/src/x86_64/mm/memblock.c:383)
     page_alloc_init_late (kbuild/src/x86_64/include/linux/find.h:208 kbuild/src/x86_64/include/linux/nodemask.h:266 kbuild/src/x86_64/mm/mm_init.c:2405)
     kernel_init_freeable (kbuild/src/x86_64/init/main.c:1325 kbuild/src/x86_64/init/main.c:1546)
     kernel_init (kbuild/src/x86_64/init/main.c:1439)
     ret_from_fork (kbuild/src/x86_64/arch/x86/kernel/process.c:145)
     ret_from_fork_asm (kbuild/src/x86_64/arch/x86/entry/entry_64.S:298)

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202307271656.447aa17e-oliver.sang@intel.com
Signed-off-by: "Mike Rapoport (IBM)" <rppt@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-28 09:47:06 -07:00
Jann Horn 6c21e066f9 mm/mempolicy: Take VMA lock before replacing policy
mbind() calls down into vma_replace_policy() without taking the per-VMA
locks, replaces the VMA's vma->vm_policy pointer, and frees the old
policy.  That's bad; a concurrent page fault might still be using the
old policy (in vma_alloc_folio()), resulting in use-after-free.

Normally this will manifest as a use-after-free read first, but it can
result in memory corruption, including because vma_alloc_folio() can
call mpol_cond_put() on the freed policy, which conditionally changes
the policy's refcount member.

This bug is specific to CONFIG_NUMA, but it does also affect non-NUMA
systems as long as the kernel was built with CONFIG_NUMA.

Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Fixes: 5e31275cc9 ("mm: add per-VMA lock and helper functions to control it")
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-28 09:44:06 -07:00
Sidhartha Kumar 6c54312f96 mm/memory-failure: fix hardware poison check in unpoison_memory()
It was pointed out[1] that using folio_test_hwpoison() is wrong as we need
to check the indiviual page that has poison.  folio_test_hwpoison() only
checks the head page so go back to using PageHWPoison().

User-visible effects include existing hwpoison-inject tests possibly
failing as unpoisoning a single subpage could lead to unpoisoning an
entire folio.  Memory unpoisoning could also not work as expected as
the function will break early due to only checking the head page and
not the actually poisoned subpage.

[1]: https://lore.kernel.org/lkml/ZLIbZygG7LqSI9xe@casper.infradead.org/

Link: https://lkml.kernel.org/r/20230717181812.167757-1-sidhartha.kumar@oracle.com
Fixes: a6fddef49e ("mm/memory-failure: convert unpoison_memory() to folios")
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reported-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-27 13:07:05 -07:00
Jann Horn d8ab9f7b64 mm: lock VMA in dup_anon_vma() before setting ->anon_vma
When VMAs are merged, dup_anon_vma() is called with `dst` pointing to the
VMA that is being expanded to cover the area previously occupied by
another VMA.  This currently happens while `dst` is not write-locked.

This means that, in the `src->anon_vma && !dst->anon_vma` case, as soon as
the assignment `dst->anon_vma = src->anon_vma` has happened, concurrent
page faults can happen on `dst` under the per-VMA lock.  This is already
icky in itself, since such page faults can now install pages into `dst`
that are attached to an `anon_vma` that is not yet tied back to the
`anon_vma` with an `anon_vma_chain`.  But if `anon_vma_clone()` fails due
to an out-of-memory error, things get much worse: `anon_vma_clone()` then
reverts `dst->anon_vma` back to NULL, and `dst` remains completely
unconnected to the `anon_vma`, even though we can have pages in the area
covered by `dst` that point to the `anon_vma`.

This means the `anon_vma` of such pages can be freed while the pages are
still mapped into userspace, which leads to UAF when a helper like
folio_lock_anon_vma_read() tries to look up the anon_vma of such a page.

This theoretically is a security bug, but I believe it is really hard to
actually trigger as an unprivileged user because it requires that you can
make an order-0 GFP_KERNEL allocation fail, and the page allocator tries
pretty hard to prevent that.

I think doing the vma_start_write() call inside dup_anon_vma() is the most
straightforward fix for now.

For a kernel-assisted reproducer, see the notes section of the patch mail.

Link: https://lkml.kernel.org/r/20230721034643.616851-1-jannh@google.com
Fixes: 5e31275cc9 ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-27 13:07:04 -07:00
Hugh Dickins 8b1cb4a2e8 mm/pagewalk: fix EFI_PGT_DUMP of espfix area
Booting x86_64 with CONFIG_EFI_PGT_DUMP=y shows messages of the form
"mm/pgtable-generic.c:53: bad pmd (____ptrval____)(8000000100077061)".

EFI_PGT_DUMP dumps all of efi_mm, including the espfix area, which is set
up with pmd entries which fit the pmd_bad() check: so 0d940a9b27 warns
and clears those entries, which would ruin running Win16 binaries.

The failing pte_offset_map() stopped such a kernel from even booting,
until a few commits later be872f83bf changed the pagewalk to tolerate
that: but it needs to be even more careful, to not spoil those entries.

I might have preferred to change init_espfix_ap() not to use "bad" pmd
entries; or to leave them out of the efi_mm dump.  But there is great
value in staying away from there, and a pagewalk check of address against
TASK_SIZE may protect from other such aberrations too.

Link: https://lkml.kernel.org/r/22bca736-4cab-9ee5-6a52-73a3b2bbe865@google.com
Closes: https://lore.kernel.org/linux-mm/CABXGCsN3JqXckWO=V7p=FhPU1tK03RE1w9UE6xL5Y86SMk209w@mail.gmail.com/
Fixes: 0d940a9b27 ("mm/pgtable: allow pte_offset_map[_lock]() to fail")
Fixes: be872f83bf ("mm/pagewalk: walk_pte_range() allow for pte_offset_map()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-27 13:07:04 -07:00
Hugh Dickins fa598952fa shmem: minor fixes to splice-read implementation
HWPoison: my reading of folio_test_hwpoison() is that it only tests the
head page of a large folio, whereas splice_folio_into_pipe() will splice
as much of the folio as it can: so for safety we should also check the
has_hwpoisoned flag, set if any of the folio's pages are hwpoisoned. 
(Perhaps that ugliness can be improved at the mm end later.)

The call to splice_zeropage_into_pipe() risked overrunning past EOF: ask
it for "part" not "len".

Link: https://lkml.kernel.org/r/32c72c9c-72a8-115f-407d-f0148f368@google.com
Fixes: bd194b1871 ("shmem: Implement splice-read")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-27 13:07:03 -07:00
Feng Tang d1836a3b2a mm/damon/core-test: initialise context before test in damon_test_set_attrs()
Running kunit test for 6.5-rc1 hits one bug:

        ok 10 damon_test_update_monitoring_result
    general protection fault, probably for non-canonical address 0x1bffa5c419cfb81: 0000 [#1] PREEMPT SMP NOPTI
    CPU: 1 PID: 110 Comm: kunit_try_catch Tainted: G                 N 6.5.0-rc2 #15
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
    RIP: 0010:damon_set_attrs+0xb9/0x120
    Code: f8 00 00 00 4c 8d 58 e0 48 39 c3 74 ba 41 ba 59 17 b7 d1 49 8b 43 10 4d
    8d 4b 10 48 8d 70 e0 49 39 c1 74 50 49 8b 40 08 31 d2 <69> 4e 18 10 27 00 00
    49 f7 30 31 d2 48 89 c5 89 c8 f7 f5 31 d2 89
    RSP: 0000:ffffc900005bfd40 EFLAGS: 00010246
    RAX: ffffffff81159fc0 RBX: ffffc900005bfeb8 RCX: 0000000000000000
    RDX: 0000000000000000 RSI: 01bffa5c419cfb69 RDI: ffffc900005bfd70
    RBP: ffffc90000013c10 R08: ffffc900005bfdc0 R09: ffffffff81ff10ed
    R10: 00000000d1b71759 R11: ffffffff81ff10dd R12: ffffc90000013a78
    R13: ffff88810eb78180 R14: ffffffff818297c0 R15: ffffc90000013c28
    FS:  0000000000000000(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 0000000002a1c001 CR4: 0000000000370ee0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     <TASK>
     damon_test_set_attrs+0x63/0x1f0
     kunit_generic_run_threadfn_adapter+0x17/0x30
     kthread+0xfd/0x130

The problem seems to be related with the damon_ctx was used without
being initialized. Fix it by adding the initialization.

Link: https://lkml.kernel.org/r/20230718052811.1065173-1-feng.tang@intel.com
Fixes: aa13779be6 ("mm/damon/core-test: add a test for damon_set_attrs()")
Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-27 13:07:03 -07:00
Linus Torvalds 379e66711b memblock: reset memblock.reserved to system init state to prevent UAF
A call to memblock_free() or memblock_phys_free() issued after memblock
 data is discarded will result in use after free in
 memblock_isolate_range().
 
 When CONFIG_KASAN is enabled, this will cause a panic early in boot.
 Without CONFIG_KASAN, there is a chance that memblock_isolate_range() might
 scribble on memory that is now in use by somebody else.
 
 Avoid those issues by making sure that memblock_discard points
 memblock.reserved.regions back at the static buffer.
 
 If memblock_free() or memblock_phys_free() is called after memblock memory
 is discarded, that will print a warning in memblock_remove_region().
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Merge tag 'fixes-2023-07-27' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock fix from Mike Rapoport:
 "A call to memblock_free() or memblock_phys_free() issued after
  memblock data is discarded will result in use after free in
  memblock_isolate_range().

  Avoid those issues by making sure that memblock_discard points
  memblock.reserved.regions back at the static buffer"

* tag 'fixes-2023-07-27' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  mm,memblock: reset memblock.reserved to system init state to prevent UAF
2023-07-27 11:37:34 -07:00
Jann Horn 657b514695 mm: lock_vma_under_rcu() must check vma->anon_vma under vma lock
lock_vma_under_rcu() tries to guarantee that __anon_vma_prepare() can't
be called in the VMA-locked page fault path by ensuring that
vma->anon_vma is set.

However, this check happens before the VMA is locked, which means a
concurrent move_vma() can concurrently call unlink_anon_vmas(), which
disassociates the VMA's anon_vma.

This means we can get UAF in the following scenario:

  THREAD 1                   THREAD 2
  ========                   ========
  <page fault>
    lock_vma_under_rcu()
      rcu_read_lock()
      mas_walk()
      check vma->anon_vma

                             mremap() syscall
                               move_vma()
                                vma_start_write()
                                 unlink_anon_vmas()
                             <syscall end>

    handle_mm_fault()
      __handle_mm_fault()
        handle_pte_fault()
          do_pte_missing()
            do_anonymous_page()
              anon_vma_prepare()
                __anon_vma_prepare()
                  find_mergeable_anon_vma()
                    mas_walk() [looks up VMA X]

                             munmap() syscall (deletes VMA X)

                    reusable_anon_vma() [called on freed VMA X]

This is a security bug if you can hit it, although an attacker would
have to win two races at once where the first race window is only a few
instructions wide.

This patch is based on some previous discussion with Linus Torvalds on
the security list.

Cc: stable@vger.kernel.org
Fixes: 5e31275cc9 ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-27 11:13:22 -07:00
Rik van Riel 9e46e4dcd9 mm,memblock: reset memblock.reserved to system init state to prevent UAF
The memblock_discard function frees the memblock.reserved.regions
array, which is good.

However, if a subsequent memblock_free (or memblock_phys_free) comes
in later, from for example ima_free_kexec_buffer, that will result in
a use after free bug in memblock_isolate_range.

When running a kernel with CONFIG_KASAN enabled, this will cause a
kernel panic very early in boot. Without CONFIG_KASAN, there is
a chance that memblock_isolate_range might scribble on memory
that is now in use by somebody else.

Avoid those issues by making sure that memblock_discard points
memblock.reserved.regions back at the static buffer.

If memblock_free is called after memblock memory is discarded, that will
print a warning in memblock_remove_region.

Signed-off-by: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/r/20230719154137.732d8525@imladris.surriel.com
Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>
2023-07-24 08:52:56 +03:00
Liam R. Howlett 2658f94d67 mm/mlock: fix vma iterator conversion of apply_vma_lock_flags()
apply_vma_lock_flags() calls mlock_fixup(), which could merge the VMA
after where the vma iterator is located.  Although this is not an issue,
the next iteration of the loop will check the start of the vma to be equal
to the locally saved 'tmp' variable and cause an incorrect failure
scenario.  Fix the error by setting tmp to the end of the vma iterator
value before restarting the loop.

There is also a potential of the error code being overwritten when the
loop terminates early.  Fix the return issue by directly returning when an
error is encountered since there is nothing to undo after the loop.

Link: https://lkml.kernel.org/r/20230711175020.4091336-1-Liam.Howlett@oracle.com
Fixes: 37598f5a9d ("mlock: convert mlock to vma iterator")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Ryan Roberts <ryan.roberts@arm.com>
  Link: https://lore.kernel.org/linux-mm/50341ca1-d582-b33a-e3d0-acb08a65166f@arm.com/
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-17 12:53:21 -07:00
Hugh Dickins 1c7873e336 mm: lock newly mapped VMA with corrected ordering
Lockdep is certainly right to complain about

  (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_write+0x2d/0x3f
                 but task is already holding lock:
  (&mapping->i_mmap_rwsem){+.+.}-{3:3}, at: mmap_region+0x4dc/0x6db

Invert those to the usual ordering.

Fixes: 33313a747e ("mm: lock newly mapped VMA which can be modified after it becomes visible")
Cc: stable@vger.kernel.org
Signed-off-by: Hugh Dickins <hughd@google.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-08 16:44:11 -07:00
Linus Torvalds 946c6b59c5 16 hotfixes. Six are cc:stable and the remainder address post-6.4 issues.
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Merge tag 'mm-hotfixes-stable-2023-07-08-10-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull hotfixes from Andrew Morton:
 "16 hotfixes. Six are cc:stable and the remainder address post-6.4
  issues"

The merge undoes the disabling of the CONFIG_PER_VMA_LOCK feature, since
it was all hopefully fixed in mainline.

* tag 'mm-hotfixes-stable-2023-07-08-10-43' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  lib: dhry: fix sleeping allocations inside non-preemptable section
  kasan, slub: fix HW_TAGS zeroing with slub_debug
  kasan: fix type cast in memory_is_poisoned_n
  mailmap: add entries for Heiko Stuebner
  mailmap: update manpage link
  bootmem: remove the vmemmap pages from kmemleak in free_bootmem_page
  MAINTAINERS: add linux-next info
  mailmap: add Markus Schneider-Pargmann
  writeback: account the number of pages written back
  mm: call arch_swap_restore() from do_swap_page()
  squashfs: fix cache race with migration
  mm/hugetlb.c: fix a bug within a BUG(): inconsistent pte comparison
  docs: update ocfs2-devel mailing list address
  MAINTAINERS: update ocfs2-devel mailing list address
  mm: disable CONFIG_PER_VMA_LOCK until its fixed
  fork: lock VMAs of the parent process when forking
2023-07-08 14:30:25 -07:00
Suren Baghdasaryan 33313a747e mm: lock newly mapped VMA which can be modified after it becomes visible
mmap_region adds a newly created VMA into VMA tree and might modify it
afterwards before dropping the mmap_lock.  This poses a problem for page
faults handled under per-VMA locks because they don't take the mmap_lock
and can stumble on this VMA while it's still being modified.  Currently
this does not pose a problem since post-addition modifications are done
only for file-backed VMAs, which are not handled under per-VMA lock.
However, once support for handling file-backed page faults with per-VMA
locks is added, this will become a race.

Fix this by write-locking the VMA before inserting it into the VMA tree.
Other places where a new VMA is added into VMA tree do not modify it
after the insertion, so do not need the same locking.

Cc: stable@vger.kernel.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-08 14:08:02 -07:00
Suren Baghdasaryan c137381f71 mm: lock a vma before stack expansion
With recent changes necessitating mmap_lock to be held for write while
expanding a stack, per-VMA locks should follow the same rules and be
write-locked to prevent page faults into the VMA being expanded. Add
the necessary locking.

Cc: stable@vger.kernel.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-08 14:08:02 -07:00
Andrey Konovalov fdb54d9660 kasan, slub: fix HW_TAGS zeroing with slub_debug
Commit 946fa0dbf2 ("mm/slub: extend redzone check to extra allocated
kmalloc space than requested") added precise kmalloc redzone poisoning to
the slub_debug functionality.

However, this commit didn't account for HW_TAGS KASAN fully initializing
the object via its built-in memory initialization feature.  Even though
HW_TAGS KASAN memory initialization contains special memory initialization
handling for when slub_debug is enabled, it does not account for in-object
slub_debug redzones.  As a result, HW_TAGS KASAN can overwrite these
redzones and cause false-positive slub_debug reports.

To fix the issue, avoid HW_TAGS KASAN memory initialization when
slub_debug is enabled altogether.  Implement this by moving the
__slub_debug_enabled check to slab_post_alloc_hook.  Common slab code
seems like a more appropriate place for a slub_debug check anyway.

Link: https://lkml.kernel.org/r/678ac92ab790dba9198f9ca14f405651b97c8502.1688561016.git.andreyknvl@google.com
Fixes: 946fa0dbf2 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Will Deacon <will@kernel.org>
Acked-by: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: kasan-dev@googlegroups.com
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:32 -07:00
Andrey Konovalov 05c56e7b43 kasan: fix type cast in memory_is_poisoned_n
Commit bb6e04a173 ("kasan: use internal prototypes matching gcc-13
builtins") introduced a bug into the memory_is_poisoned_n implementation:
it effectively removed the cast to a signed integer type after applying
KASAN_GRANULE_MASK.

As a result, KASAN started failing to properly check memset, memcpy, and
other similar functions.

Fix the bug by adding the cast back (through an additional signed integer
variable to make the code more readable).

Link: https://lkml.kernel.org/r/8c9e0251c2b8b81016255709d4ec42942dcaf018.1688431866.git.andreyknvl@google.com
Fixes: bb6e04a173 ("kasan: use internal prototypes matching gcc-13 builtins")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:32 -07:00
Matthew Wilcox (Oracle) 8344a3d44b writeback: account the number of pages written back
nr_to_write is a count of pages, so we need to decrease it by the number
of pages in the folio we just wrote, not by 1.  Most callers specify
either LONG_MAX or 1, so are unaffected, but writeback_sb_inodes() might
end up writing 512x as many pages as it asked for.

Dave added:

: XFS is the only filesystem this would affect, right?  AFAIA, nothing
: else enables large folios and uses writeback through
: write_cache_pages() at this point...
: 
: In which case, I'd be surprised if much difference, if any, gets
: noticed by anyone.

Link: https://lkml.kernel.org/r/20230628185548.981888-1-willy@infradead.org
Fixes: 793917d997 ("mm/readahead: Add large folio readahead")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:30 -07:00
Peter Collingbourne 6dca4ac6fc mm: call arch_swap_restore() from do_swap_page()
Commit c145e0b47c ("mm: streamline COW logic in do_swap_page()") moved
the call to swap_free() before the call to set_pte_at(), which meant that
the MTE tags could end up being freed before set_pte_at() had a chance to
restore them.  Fix it by adding a call to the arch_swap_restore() hook
before the call to swap_free().

Link: https://lkml.kernel.org/r/20230523004312.1807357-2-pcc@google.com
Link: https://linux-review.googlesource.com/id/I6470efa669e8bd2f841049b8c61020c510678965
Fixes: c145e0b47c ("mm: streamline COW logic in do_swap_page()")
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reported-by: Qun-wei Lin <Qun-wei.Lin@mediatek.com>
Closes: https://lore.kernel.org/all/5050805753ac469e8d727c797c2218a9d780d434.camel@mediatek.com/
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>	[6.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:30 -07:00
John Hubbard 191fcdb6c9 mm/hugetlb.c: fix a bug within a BUG(): inconsistent pte comparison
The following crash happens for me when running the -mm selftests (below).
Specifically, it happens while running the uffd-stress subtests:

kernel BUG at mm/hugetlb.c:7249!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 3238 Comm: uffd-stress Not tainted 6.4.0-hubbard-github+ #109
Hardware name: ASUS X299-A/PRIME X299-A, BIOS 1503 08/03/2018
RIP: 0010:huge_pte_alloc+0x12c/0x1a0
...
Call Trace:
 <TASK>
 ? __die_body+0x63/0xb0
 ? die+0x9f/0xc0
 ? do_trap+0xab/0x180
 ? huge_pte_alloc+0x12c/0x1a0
 ? do_error_trap+0xc6/0x110
 ? huge_pte_alloc+0x12c/0x1a0
 ? handle_invalid_op+0x2c/0x40
 ? huge_pte_alloc+0x12c/0x1a0
 ? exc_invalid_op+0x33/0x50
 ? asm_exc_invalid_op+0x16/0x20
 ? __pfx_put_prev_task_idle+0x10/0x10
 ? huge_pte_alloc+0x12c/0x1a0
 hugetlb_fault+0x1a3/0x1120
 ? finish_task_switch+0xb3/0x2a0
 ? lock_is_held_type+0xdb/0x150
 handle_mm_fault+0xb8a/0xd40
 ? find_vma+0x5d/0xa0
 do_user_addr_fault+0x257/0x5d0
 exc_page_fault+0x7b/0x1f0
 asm_exc_page_fault+0x22/0x30

That happens because a BUG() statement in huge_pte_alloc() attempts to
check that a pte, if present, is a hugetlb pte, but it does so in a
non-lockless-safe manner that leads to a false BUG() report.

We got here due to a couple of bugs, each of which by itself was not quite
enough to cause a problem:

First of all, before commit c33c794828f2("mm: ptep_get() conversion"), the
BUG() statement in huge_pte_alloc() was itself fragile: it relied upon
compiler behavior to only read the pte once, despite using it twice in the
same conditional.

Next, commit c33c794828 ("mm: ptep_get() conversion") broke that
delicate situation, by causing all direct pte reads to be done via
READ_ONCE().  And so READ_ONCE() got called twice within the same BUG()
conditional, leading to comparing (potentially, occasionally) different
versions of the pte, and thus to false BUG() reports.

Fix this by taking a single snapshot of the pte before using it in the
BUG conditional.

Now, that commit is only partially to blame here but, people doing
bisections will invariably land there, so this will help them find a fix
for a real crash.  And also, the previous behavior was unlikely to ever
expose this bug--it was fragile, yet not actually broken.

So that's why I chose this commit for the Fixes tag, rather than the
commit that created the original BUG() statement.

Link: https://lkml.kernel.org/r/20230701010442.2041858-1-jhubbard@nvidia.com
Fixes: c33c794828 ("mm: ptep_get() conversion")
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: James Houghton <jthoughton@google.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:29 -07:00
Suren Baghdasaryan f96c486703 mm: disable CONFIG_PER_VMA_LOCK until its fixed
A memory corruption was reported in [1] with bisection pointing to the
patch [2] enabling per-VMA locks for x86.  Disable per-VMA locks config to
prevent this issue until the fix is confirmed.  This is expected to be a
temporary measure.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=217624
[2] https://lore.kernel.org/all/20230227173632.3292573-30-surenb@google.com

Link: https://lkml.kernel.org/r/20230706011400.2949242-3-surenb@google.com
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Closes: https://lore.kernel.org/all/dbdef34c-3a07-5951-e1ae-e9c6e3cdf51b@kernel.org/
Reported-by: Jacob Young <jacobly.alt@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217624
Fixes: 0bff0aaea0 ("x86/mm: try VMA lock-based page fault handling first")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Holger Hoffstätte <holger@applied-asynchrony.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:29 -07:00
Linus Torvalds 6cd06ab12d gup: make the stack expansion warning a bit more targeted
I added a warning about about GUP no longer expanding the stack in
commit a425ac5365 ("gup: add warning if some caller would seem to want
stack expansion"), but didn't really expect anybody to hit it.

And it's true that nobody seems to have hit a _real_ case yet, but we
certainly have a number of reports of false positives.  Which not only
causes extra noise in itself, but might also end up hiding any real
cases if they do exist.

So let's tighten up the warning condition, and replace the simplistic

	vma = find_vma(mm, start);
	if (vma && (start < vma->vm_start)) {
		WARN_ON_ONCE(vma->vm_flags & VM_GROWSDOWN);

with a

	vma = gup_vma_lookup(mm, start);

helper function which works otherwise like just "vma_lookup()", but with
some heuristics for when to warn about gup no longer causing stack
expansion.

In particular, don't just warn for "below the stack", but warn if it's
_just_ below the stack (with "just below" arbitrarily defined as 64kB,
because why not?).  And rate-limit it to at most once per hour, which
means that any false positives shouldn't completely hide subsequent
reports, but we won't be flooding the logs about it either.

The previous code triggered when some GUP user (chromium crashpad)
accessing past the end of the previous vma, for example.  That has never
expanded the stack, it just causes GUP to return early, and as such we
shouldn't be warning about it.

This is still going trigger the randomized testers, but to mitigate the
noise from that, use "dump_stack()" instead of "WARN_ON_ONCE()" to get
the kernel call chain.  We'll get the relevant information, but syzbot
shouldn't get too upset about it.

Also, don't even bother with the GROWSUP case, which would be using
different heuristics entirely, but only happens on parisc.

Reported-by: kernel test robot <oliver.sang@intel.com>
Reported-by: John Hubbard <jhubbard@nvidia.com>
Reported-by: syzbot+6cf44e127903fdf9d929@syzkaller.appspotmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-05 09:33:31 -07:00
Linus Torvalds b5641a5d8b mm: don't do validate_mm() unnecessarily and without mmap locking
This is an addition to commit ae80b40419 ("mm: validate the mm before
dropping the mmap lock"), because it turns out there were two problems,
but lockdep just stopped complaining after finding the first one.

The do_vmi_align_munmap() function now drops the mmap lock after doing
the validate_mm() call, but it turns out that one of the callers then
immediately calls validate_mm() again.

That's both a bit silly, and now (again) happens without the mmap lock
held.

So just remove that validate_mm() call from the caller, but make sure to
not lose any coverage by doing that mm sanity checking in the error path
of do_vmi_align_munmap() too.

Reported-and-tested-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/ZKN6CdkKyxBShPHi@xsang-OptiPlex-9020/
Fixes: 408579cd62 ("mm: Update do_vmi_align_munmap() return semantics")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-04 07:22:59 -07:00
Linus Torvalds ae80b40419 mm: validate the mm before dropping the mmap lock
Commit 408579cd62 ("mm: Update do_vmi_align_munmap() return
semantics") made the return value and locking semantics of
do_vmi_align_munmap() more straightforward, but in the process it ended
up unlocking the mmap lock just a tad too early: the debug code doing
the mmap layout validation still needs to run with the lock held, or
things might change under it while it's trying to validate things.

So just move the unlocking to after the validate_mm() call.

Reported-by: kernel test robot <oliver.sang@intel.com>
Link: https://lore.kernel.org/lkml/ZKIsoMOT71uwCIZX@xsang-OptiPlex-9020/
Fixes: 408579cd62 ("mm: Update do_vmi_align_munmap() return semantics")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-03 10:08:50 -07:00
Liam R. Howlett 408579cd62 mm: Update do_vmi_align_munmap() return semantics
Since do_vmi_align_munmap() will always honor the downgrade request on
the success, the callers no longer have to deal with confusing return
codes.  Since all callers that request downgrade actually want the lock
to be dropped, change the downgrade to an unlock request.

Note that the lock still needs to be held in read mode during the page
table clean up to avoid races with a map request.

Update do_vmi_align_munmap() to return 0 for success.  Clean up the
callers and comments to always expect the unlock to be honored on the
success path.  The error path will always leave the lock untouched.

As part of the cleanup, the wrapper function do_vmi_munmap() and callers
to the wrapper are also updated.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/linux-mm/20230629191414.1215929-1-willy@infradead.org/
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-01 08:10:56 -07:00
Matthew Wilcox (Oracle) e4bd84c069 mm: Always downgrade mmap_lock if requested
Now that stack growth must always hold the mmap_lock for write, we can
always downgrade the mmap_lock to read and safely unmap pages from the
page table, even if we're next to a stack.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-01 08:10:56 -07:00
Max Filippov 03f889378f xtensa: fix lock_mm_and_find_vma in case VMA not found
MMU version of lock_mm_and_find_vma releases the mm lock before
returning when VMA is not found. Do the same in noMMU version.
This fixes hang on an attempt to handle protection fault.

Fixes: d85a143b69 ("xtensa: fix NOMMU build with lock_mm_and_find_vma() conversion")
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-07-01 08:00:05 -07:00
Linus Torvalds d85a143b69 xtensa: fix NOMMU build with lock_mm_and_find_vma() conversion
It turns out that xtensa has a really odd configuration situation: you
can do a no-MMU config, but still have the page fault code enabled.
Which doesn't sound all that sensible, but it turns out that xtensa can
have protection faults even without the MMU, and we have this:

    config PFAULT
        bool "Handle protection faults" if EXPERT && !MMU
        default y
        help
          Handle protection faults. MMU configurations must enable it.
          noMMU configurations may disable it if used memory map never
          generates protection faults or faults are always fatal.

          If unsure, say Y.

which completely violated my expectations of the page fault handling.

End result: Guenter reports that the xtensa no-MMU builds all fail with

  arch/xtensa/mm/fault.c: In function ‘do_page_fault’:
  arch/xtensa/mm/fault.c:133:8: error: implicit declaration of function ‘lock_mm_and_find_vma’

because I never exposed the new lock_mm_and_find_vma() function for the
no-MMU case.

Doing so is simple enough, and fixes the problem.

Reported-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: a050ba1e74 ("mm/fault: convert remaining simple cases to lock_mm_and_find_vma()")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-30 21:08:05 -07:00
Linus Torvalds 075e333591 memblock: small updates for 6.5-rc1
* add test for memblock_alloc_node()
 * minor coding style fixes
 * add flags and nid info in memblock debugfs
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Merge tag 'memblock-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock updates from Mike Rapoport:

 - add test for memblock_alloc_node()

 - minor coding style fixes

 - add flags and nid info in memblock debugfs

* tag 'memblock-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock: Update nid info in memblock debugfs
  memblock: Add flags and nid info in memblock debugfs
  Fix some coding style errors in memblock.c
  Add tests for memblock_alloc_node()
2023-06-29 23:21:20 -07:00
Linus Torvalds 43ec8a620b Fix error return from do_vmi_align_munmap()
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Merge tag 'unmap-fix-20230629' of git://git.infradead.org/users/dwmw2/linux

Pull mm fix from David Woodhouse:
 "Fix error return from do_vmi_align_munmap()"

* tag 'unmap-fix-20230629' of git://git.infradead.org/users/dwmw2/linux:
  mm/mmap: Fix error return in do_vmi_align_munmap()
2023-06-29 17:38:54 -07:00
Linus Torvalds 632f54b4d6 slab updates for 6.5
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Merge tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:

 - SLAB deprecation:

   Following the discussion at LSF/MM 2023 [1] and no objections, the
   SLAB allocator is deprecated by renaming the config option (to make
   its users notice) to CONFIG_SLAB_DEPRECATED with updated help text.
   SLUB should be used instead. Existing defconfigs with CONFIG_SLAB are
   also updated.

 - SLAB_NO_MERGE kmem_cache flag (Jesper Dangaard Brouer):

   There are (very limited) cases where kmem_cache merging is
   undesirable, and existing ways to prevent it are hacky. Introduce a
   new flag to do that cleanly and convert the existing hacky users.
   Btrfs plans to use this for debug kernel builds (that use case is
   always fine), networking for performance reasons (that should be very
   rare).

 - Replace the usage of weak PRNGs (David Keisar Schmidt):

   In addition to using stronger RNGs for the security related features,
   the code is a bit cleaner.

 - Misc code cleanups (SeongJae Parki, Xiongwei Song, Zhen Lei, and
   zhaoxinchao)

Link: https://lwn.net/Articles/932201/ [1]

* tag 'slab-for-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab_common: use SLAB_NO_MERGE instead of negative refcount
  mm/slab: break up RCU readers on SLAB_TYPESAFE_BY_RCU example code
  mm/slab: add a missing semicolon on SLAB_TYPESAFE_BY_RCU example code
  mm/slab_common: reduce an if statement in create_cache()
  mm/slab: introduce kmem_cache flag SLAB_NO_MERGE
  mm/slab: rename CONFIG_SLAB to CONFIG_SLAB_DEPRECATED
  mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR
  mm/slab_common: Replace invocation of weak PRNG
  mm/slab: Replace invocation of weak PRNG
  slub: Don't read nr_slabs and total_objects directly
  slub: Remove slabs_node() function
  slub: Remove CONFIG_SMP defined check
  slub: Put objects_show() into CONFIG_SLUB_DEBUG enabled block
  slub: Correct the error code when slab_kset is NULL
  mm/slab: correct return values in comment for _kmem_cache_create()
2023-06-29 16:34:12 -07:00
Linus Torvalds eee9c708cc gup: avoid stack expansion warning for known-good case
In commit a425ac5365 ("gup: add warning if some caller would seem to
want stack expansion") I added a temporary warning to catch any strange
GUP users that would be impacted by the fact that GUP no longer extends
the stack.

But it turns out that the warning is most easily triggered through
__access_remote_vm(), that already knows to expand the stack - it just
does it *after* calling GUP.  So the warning is easy to trigger by just
running gdb (or similar) and accessing things remotely under the stack.

This just adds a temporary extra "expand stack early" to avoid the
warning for the already converted case - not because the warning is bad,
but because getting the warning for this known good case would then hide
any subsequent warnings for any actually interesting cases.

Let's try to remember to revert this change when we remove the warnings.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-29 12:36:47 -07:00
Hugh Dickins e8c716bc68 mm/khugepaged: fix regression in collapse_file()
There is no xas_pause(&xas) in collapse_file()'s main loop, at the points
where it does xas_unlock_irq(&xas) and then continues.

That would explain why, once two weeks ago and twice yesterday, I have
hit the VM_BUG_ON_PAGE(page != xas_load(&xas), page) since "mm/khugepaged:
fix iteration in collapse_file" removed the xas_set(&xas, index) just
before it: xas.xa_node could be left pointing to a stale node, if there
was concurrent activity on the file which transformed its xarray.

I tried inserting xas_pause()s, but then even bootup crashed on that
VM_BUG_ON_PAGE(): there appears to be a subtle "nextness" implicit in
xas_pause().

xas_next() and xas_pause() are good for use in simple loops, but not in
this one: xas_set() worked well until now, so use xas_set(&xas, index)
explicitly at the head of the loop; and change that VM_BUG_ON_PAGE() not
to need its own xas_set(), and not to interfere with the xa_state (which
would probably stop the crashes from xas_pause(), but I trust that less).

The user-visible effects of this bug (if VM_BUG_ONs are configured out)
would be data loss and data leak - potentially - though in practice I
expect it is more likely that a subsequent check (e.g. on mapping or on
nr_none) would notice an inconsistency, and just abandon the collapse.

Link: https://lore.kernel.org/linux-mm/f18e4b64-3f88-a8ab-56cc-d1f5f9c58d4@google.com/
Fixes: c8a8f3b4a9 ("mm/khugepaged: fix iteration in collapse_file")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Stevens <stevensd@chromium.org>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-29 09:41:45 -07:00
Linus Torvalds 9471f1f2f5 Merge branch 'expand-stack'
This modifies our user mode stack expansion code to always take the
mmap_lock for writing before modifying the VM layout.

It's actually something we always technically should have done, but
because we didn't strictly need it, we were being lazy ("opportunistic"
sounds so much better, doesn't it?) about things, and had this hack in
place where we would extend the stack vma in-place without doing the
proper locking.

And it worked fine.  We just needed to change vm_start (or, in the case
of grow-up stacks, vm_end) and together with some special ad-hoc locking
using the anon_vma lock and the mm->page_table_lock, it all was fairly
straightforward.

That is, it was all fine until Ruihan Li pointed out that now that the
vma layout uses the maple tree code, we *really* don't just change
vm_start and vm_end any more, and the locking really is broken.  Oops.

It's not actually all _that_ horrible to fix this once and for all, and
do proper locking, but it's a bit painful.  We have basically three
different cases of stack expansion, and they all work just a bit
differently:

 - the common and obvious case is the page fault handling. It's actually
   fairly simple and straightforward, except for the fact that we have
   something like 24 different versions of it, and you end up in a maze
   of twisty little passages, all alike.

 - the simplest case is the execve() code that creates a new stack.
   There are no real locking concerns because it's all in a private new
   VM that hasn't been exposed to anybody, but lockdep still can end up
   unhappy if you get it wrong.

 - and finally, we have GUP and page pinning, which shouldn't really be
   expanding the stack in the first place, but in addition to execve()
   we also use it for ptrace(). And debuggers do want to possibly access
   memory under the stack pointer and thus need to be able to expand the
   stack as a special case.

None of these cases are exactly complicated, but the page fault case in
particular is just repeated slightly differently many many times.  And
ia64 in particular has a fairly complicated situation where you can have
both a regular grow-down stack _and_ a special grow-up stack for the
register backing store.

So to make this slightly more manageable, the bulk of this series is to
first create a helper function for the most common page fault case, and
convert all the straightforward architectures to it.

Thus the new 'lock_mm_and_find_vma()' helper function, which ends up
being used by x86, arm, powerpc, mips, riscv, alpha, arc, csky, hexagon,
loongarch, nios2, sh, sparc32, and xtensa.  So we not only convert more
than half the architectures, we now have more shared code and avoid some
of those twisty little passages.

And largely due to this common helper function, the full diffstat of
this series ends up deleting more lines than it adds.

That still leaves eight architectures (ia64, m68k, microblaze, openrisc,
parisc, s390, sparc64 and um) that end up doing 'expand_stack()'
manually because they are doing something slightly different from the
normal pattern.  Along with the couple of special cases in execve() and
GUP.

So there's a couple of patches that first create 'locked' helper
versions of the stack expansion functions, so that there's a obvious
path forward in the conversion.  The execve() case is then actually
pretty simple, and is a nice cleanup from our old "grow-up stackls are
special, because at execve time even they grow down".

The #ifdef CONFIG_STACK_GROWSUP in that code just goes away, because
it's just more straightforward to write out the stack expansion there
manually, instead od having get_user_pages_remote() do it for us in some
situations but not others and have to worry about locking rules for GUP.

And the final step is then to just convert the remaining odd cases to a
new world order where 'expand_stack()' is called with the mmap_lock held
for reading, but where it might drop it and upgrade it to a write, only
to return with it held for reading (in the success case) or with it
completely dropped (in the failure case).

In the process, we remove all the stack expansion from GUP (where
dropping the lock wouldn't be ok without special rules anyway), and add
it in manually to __access_remote_vm() for ptrace().

Thanks to Adrian Glaubitz and Frank Scheiner who tested the ia64 cases.
Everything else here felt pretty straightforward, but the ia64 rules for
stack expansion are really quite odd and very different from everything
else.  Also thanks to Vegard Nossum who caught me getting one of those
odd conditions entirely the wrong way around.

Anyway, I think I want to actually move all the stack expansion code to
a whole new file of its own, rather than have it split up between
mm/mmap.c and mm/memory.c, but since this will have to be backported to
the initial maple tree vma introduction anyway, I tried to keep the
patches _fairly_ minimal.

Also, while I don't think it's valid to expand the stack from GUP, the
final patch in here is a "warn if some crazy GUP user wants to try to
expand the stack" patch.  That one will be reverted before the final
release, but it's left to catch any odd cases during the merge window
and release candidates.

Reported-by: Ruihan Li <lrh2000@pku.edu.cn>

* branch 'expand-stack':
  gup: add warning if some caller would seem to want stack expansion
  mm: always expand the stack with the mmap write lock held
  execve: expand new process stack manually ahead of time
  mm: make find_extend_vma() fail if write lock not held
  powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()
  mm/fault: convert remaining simple cases to lock_mm_and_find_vma()
  arm/mm: Convert to using lock_mm_and_find_vma()
  riscv/mm: Convert to using lock_mm_and_find_vma()
  mips/mm: Convert to using lock_mm_and_find_vma()
  powerpc/mm: Convert to using lock_mm_and_find_vma()
  arm64/mm: Convert to using lock_mm_and_find_vma()
  mm: make the page fault mmap locking killable
  mm: introduce new 'lock_mm_and_find_vma()' page fault helper
2023-06-28 20:35:21 -07:00
Linus Torvalds 3a8a670eee Networking changes for 6.5.
Core
 ----
 
  - Rework the sendpage & splice implementations. Instead of feeding
    data into sockets page by page extend sendmsg handlers to support
    taking a reference on the data, controlled by a new flag called
    MSG_SPLICE_PAGES. Rework the handling of unexpected-end-of-file
    to invoke an additional callback instead of trying to predict what
    the right combination of MORE/NOTLAST flags is.
    Remove the MSG_SENDPAGE_NOTLAST flag completely.
 
  - Implement SCM_PIDFD, a new type of CMSG type analogous to
    SCM_CREDENTIALS, but it contains pidfd instead of plain pid.
 
  - Enable socket busy polling with CONFIG_RT.
 
  - Improve reliability and efficiency of reporting for ref_tracker.
 
  - Auto-generate a user space C library for various Netlink families.
 
 Protocols
 ---------
 
  - Allow TCP to shrink the advertised window when necessary, prevent
    sk_rcvbuf auto-tuning from growing the window all the way up to
    tcp_rmem[2].
 
  - Use per-VMA locking for "page-flipping" TCP receive zerocopy.
 
  - Prepare TCP for device-to-device data transfers, by making sure
    that payloads are always attached to skbs as page frags.
 
  - Make the backoff time for the first N TCP SYN retransmissions
    linear. Exponential backoff is unnecessarily conservative.
 
  - Create a new MPTCP getsockopt to retrieve all info (MPTCP_FULL_INFO).
 
  - Avoid waking up applications using TLS sockets until we have
    a full record.
 
  - Allow using kernel memory for protocol ioctl callbacks, paving
    the way to issuing ioctls over io_uring.
 
  - Add nolocalbypass option to VxLAN, forcing packets to be fully
    encapsulated even if they are destined for a local IP address.
 
  - Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure
    in-kernel ECMP implementation (e.g. Open vSwitch) select the same
    link for all packets. Support L4 symmetric hashing in Open vSwitch.
 
  - PPPoE: make number of hash bits configurable.
 
  - Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client
    (ipconfig).
 
  - Add layer 2 miss indication and filtering, allowing higher layers
    (e.g. ACL filters) to make forwarding decisions based on whether
    packet matched forwarding state in lower devices (bridge).
 
  - Support matching on Connectivity Fault Management (CFM) packets.
 
  - Hide the "link becomes ready" IPv6 messages by demoting their
    printk level to debug.
 
  - HSR: don't enable promiscuous mode if device offloads the proto.
 
  - Support active scanning in IEEE 802.15.4.
 
  - Continue work on Multi-Link Operation for WiFi 7.
 
 BPF
 ---
 
  - Add precision propagation for subprogs and callbacks. This allows
    maintaining verification efficiency when subprograms are used,
    or in fact passing the verifier at all for complex programs,
    especially those using open-coded iterators.
 
  - Improve BPF's {g,s}setsockopt() length handling. Previously BPF
    assumed the length is always equal to the amount of written data.
    But some protos allow passing a NULL buffer to discover what
    the output buffer *should* be, without writing anything.
 
  - Accept dynptr memory as memory arguments passed to helpers.
 
  - Add routing table ID to bpf_fib_lookup BPF helper.
 
  - Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands.
 
  - Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark
    maps as read-only).
 
  - Show target_{obj,btf}_id in tracing link fdinfo.
 
  - Addition of several new kfuncs (most of the names are self-explanatory):
    - Add a set of new dynptr kfuncs: bpf_dynptr_adjust(),
      bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size()
      and bpf_dynptr_clone().
    - bpf_task_under_cgroup()
    - bpf_sock_destroy() - force closing sockets
    - bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs
 
 Netfilter
 ---------
 
  - Relax set/map validation checks in nf_tables. Allow checking
    presence of an entry in a map without using the value.
 
  - Increase ip_vs_conn_tab_bits range for 64BIT builds.
 
  - Allow updating size of a set.
 
  - Improve NAT tuple selection when connection is closing.
 
 Driver API
 ----------
 
  - Integrate netdev with LED subsystem, to allow configuring HW
    "offloaded" blinking of LEDs based on link state and activity
    (i.e. packets coming in and out).
 
  - Support configuring rate selection pins of SFP modules.
 
  - Factor Clause 73 auto-negotiation code out of the drivers, provide
    common helper routines.
 
  - Add more fool-proof helpers for managing lifetime of MDIO devices
    associated with the PCS layer.
 
  - Allow drivers to report advanced statistics related to Time Aware
    scheduler offload (taprio).
 
  - Allow opting out of VF statistics in link dump, to allow more VFs
    to fit into the message.
 
  - Split devlink instance and devlink port operations.
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - Synopsys EMAC4 IP support (stmmac)
    - Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches
    - Marvell 88E6250 7 port switches
    - Microchip LAN8650/1 Rev.B0 PHYs
    - MediaTek MT7981/MT7988 built-in 1GE PHY driver
 
  - WiFi:
    - Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps
    - Realtek RTL8723DS (SDIO variant)
    - Realtek RTL8851BE
 
  - CAN:
    - Fintek F81604
 
 Drivers
 -------
 
  - Ethernet NICs:
    - Intel (100G, ice):
      - support dynamic interrupt allocation
      - use meta data match instead of VF MAC addr on slow-path
    - nVidia/Mellanox:
      - extend link aggregation to handle 4, rather than just 2 ports
      - spawn sub-functions without any features by default
    - OcteonTX2:
      - support HTB (Tx scheduling/QoS) offload
      - make RSS hash generation configurable
      - support selecting Rx queue using TC filters
    - Wangxun (ngbe/txgbe):
      - add basic Tx/Rx packet offloads
      - add phylink support (SFP/PCS control)
    - Freescale/NXP (enetc):
      - report TAPRIO packet statistics
    - Solarflare/AMD:
      - support matching on IP ToS and UDP source port of outer header
      - VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6
      - add devlink dev info support for EF10
 
  - Virtual NICs:
    - Microsoft vNIC:
      - size the Rx indirection table based on requested configuration
      - support VLAN tagging
    - Amazon vNIC:
      - try to reuse Rx buffers if not fully consumed, useful for ARM
        servers running with 16kB pages
    - Google vNIC:
      - support TCP segmentation of >64kB frames
 
  - Ethernet embedded switches:
    - Marvell (mv88e6xxx):
      - enable USXGMII (88E6191X)
    - Microchip:
     - lan966x: add support for Egress Stage 0 ACL engine
     - lan966x: support mapping packet priority to internal switch
       priority (based on PCP or DSCP)
 
  - Ethernet PHYs:
    - Broadcom PHYs:
      - support for Wake-on-LAN for BCM54210E/B50212E
      - report LPI counter
    - Microsemi PHYs: support RGMII delay configuration (VSC85xx)
    - Micrel PHYs: receive timestamp in the frame (LAN8841)
    - Realtek PHYs: support optional external PHY clock
    - Altera TSE PCS: merge the driver into Lynx PCS which it is
      a variant of
 
  - CAN: Kvaser PCIEcan:
    - support packet timestamping
 
  - WiFi:
    - Intel (iwlwifi):
      - major update for new firmware and Multi-Link Operation (MLO)
      - configuration rework to drop test devices and split
        the different families
      - support for segmented PNVM images and power tables
      - new vendor entries for PPAG (platform antenna gain) feature
    - Qualcomm 802.11ax (ath11k):
      - Multiple Basic Service Set Identifier (MBSSID) and
        Enhanced MBSSID Advertisement (EMA) support in AP mode
      - support factory test mode
    - RealTek (rtw89):
      - add RSSI based antenna diversity
      - support U-NII-4 channels on 5 GHz band
    - RealTek (rtl8xxxu):
      - AP mode support for 8188f
      - support USB RX aggregation for the newer chips
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking changes from Jakub Kicinski:
 "WiFi 7 and sendpage changes are the biggest pieces of work for this
  release. The latter will definitely require fixes but I think that we
  got it to a reasonable point.

  Core:

   - Rework the sendpage & splice implementations

     Instead of feeding data into sockets page by page extend sendmsg
     handlers to support taking a reference on the data, controlled by a
     new flag called MSG_SPLICE_PAGES

     Rework the handling of unexpected-end-of-file to invoke an
     additional callback instead of trying to predict what the right
     combination of MORE/NOTLAST flags is

     Remove the MSG_SENDPAGE_NOTLAST flag completely

   - Implement SCM_PIDFD, a new type of CMSG type analogous to
     SCM_CREDENTIALS, but it contains pidfd instead of plain pid

   - Enable socket busy polling with CONFIG_RT

   - Improve reliability and efficiency of reporting for ref_tracker

   - Auto-generate a user space C library for various Netlink families

  Protocols:

   - Allow TCP to shrink the advertised window when necessary, prevent
     sk_rcvbuf auto-tuning from growing the window all the way up to
     tcp_rmem[2]

   - Use per-VMA locking for "page-flipping" TCP receive zerocopy

   - Prepare TCP for device-to-device data transfers, by making sure
     that payloads are always attached to skbs as page frags

   - Make the backoff time for the first N TCP SYN retransmissions
     linear. Exponential backoff is unnecessarily conservative

   - Create a new MPTCP getsockopt to retrieve all info
     (MPTCP_FULL_INFO)

   - Avoid waking up applications using TLS sockets until we have a full
     record

   - Allow using kernel memory for protocol ioctl callbacks, paving the
     way to issuing ioctls over io_uring

   - Add nolocalbypass option to VxLAN, forcing packets to be fully
     encapsulated even if they are destined for a local IP address

   - Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure
     in-kernel ECMP implementation (e.g. Open vSwitch) select the same
     link for all packets. Support L4 symmetric hashing in Open vSwitch

   - PPPoE: make number of hash bits configurable

   - Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client
     (ipconfig)

   - Add layer 2 miss indication and filtering, allowing higher layers
     (e.g. ACL filters) to make forwarding decisions based on whether
     packet matched forwarding state in lower devices (bridge)

   - Support matching on Connectivity Fault Management (CFM) packets

   - Hide the "link becomes ready" IPv6 messages by demoting their
     printk level to debug

   - HSR: don't enable promiscuous mode if device offloads the proto

   - Support active scanning in IEEE 802.15.4

   - Continue work on Multi-Link Operation for WiFi 7

  BPF:

   - Add precision propagation for subprogs and callbacks. This allows
     maintaining verification efficiency when subprograms are used, or
     in fact passing the verifier at all for complex programs,
     especially those using open-coded iterators

   - Improve BPF's {g,s}setsockopt() length handling. Previously BPF
     assumed the length is always equal to the amount of written data.
     But some protos allow passing a NULL buffer to discover what the
     output buffer *should* be, without writing anything

   - Accept dynptr memory as memory arguments passed to helpers

   - Add routing table ID to bpf_fib_lookup BPF helper

   - Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands

   - Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark
     maps as read-only)

   - Show target_{obj,btf}_id in tracing link fdinfo

   - Addition of several new kfuncs (most of the names are
     self-explanatory):
      - Add a set of new dynptr kfuncs: bpf_dynptr_adjust(),
        bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size()
        and bpf_dynptr_clone().
      - bpf_task_under_cgroup()
      - bpf_sock_destroy() - force closing sockets
      - bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs

  Netfilter:

   - Relax set/map validation checks in nf_tables. Allow checking
     presence of an entry in a map without using the value

   - Increase ip_vs_conn_tab_bits range for 64BIT builds

   - Allow updating size of a set

   - Improve NAT tuple selection when connection is closing

  Driver API:

   - Integrate netdev with LED subsystem, to allow configuring HW
     "offloaded" blinking of LEDs based on link state and activity
     (i.e. packets coming in and out)

   - Support configuring rate selection pins of SFP modules

   - Factor Clause 73 auto-negotiation code out of the drivers, provide
     common helper routines

   - Add more fool-proof helpers for managing lifetime of MDIO devices
     associated with the PCS layer

   - Allow drivers to report advanced statistics related to Time Aware
     scheduler offload (taprio)

   - Allow opting out of VF statistics in link dump, to allow more VFs
     to fit into the message

   - Split devlink instance and devlink port operations

  New hardware / drivers:

   - Ethernet:
      - Synopsys EMAC4 IP support (stmmac)
      - Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches
      - Marvell 88E6250 7 port switches
      - Microchip LAN8650/1 Rev.B0 PHYs
      - MediaTek MT7981/MT7988 built-in 1GE PHY driver

   - WiFi:
      - Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps
      - Realtek RTL8723DS (SDIO variant)
      - Realtek RTL8851BE

   - CAN:
      - Fintek F81604

  Drivers:

   - Ethernet NICs:
      - Intel (100G, ice):
         - support dynamic interrupt allocation
         - use meta data match instead of VF MAC addr on slow-path
      - nVidia/Mellanox:
         - extend link aggregation to handle 4, rather than just 2 ports
         - spawn sub-functions without any features by default
      - OcteonTX2:
         - support HTB (Tx scheduling/QoS) offload
         - make RSS hash generation configurable
         - support selecting Rx queue using TC filters
      - Wangxun (ngbe/txgbe):
         - add basic Tx/Rx packet offloads
         - add phylink support (SFP/PCS control)
      - Freescale/NXP (enetc):
         - report TAPRIO packet statistics
      - Solarflare/AMD:
         - support matching on IP ToS and UDP source port of outer
           header
         - VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6
         - add devlink dev info support for EF10

   - Virtual NICs:
      - Microsoft vNIC:
         - size the Rx indirection table based on requested
           configuration
         - support VLAN tagging
      - Amazon vNIC:
         - try to reuse Rx buffers if not fully consumed, useful for ARM
           servers running with 16kB pages
      - Google vNIC:
         - support TCP segmentation of >64kB frames

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - enable USXGMII (88E6191X)
      - Microchip:
         - lan966x: add support for Egress Stage 0 ACL engine
         - lan966x: support mapping packet priority to internal switch
           priority (based on PCP or DSCP)

   - Ethernet PHYs:
      - Broadcom PHYs:
         - support for Wake-on-LAN for BCM54210E/B50212E
         - report LPI counter
      - Microsemi PHYs: support RGMII delay configuration (VSC85xx)
      - Micrel PHYs: receive timestamp in the frame (LAN8841)
      - Realtek PHYs: support optional external PHY clock
      - Altera TSE PCS: merge the driver into Lynx PCS which it is a
        variant of

   - CAN: Kvaser PCIEcan:
      - support packet timestamping

   - WiFi:
      - Intel (iwlwifi):
         - major update for new firmware and Multi-Link Operation (MLO)
         - configuration rework to drop test devices and split the
           different families
         - support for segmented PNVM images and power tables
         - new vendor entries for PPAG (platform antenna gain) feature
      - Qualcomm 802.11ax (ath11k):
         - Multiple Basic Service Set Identifier (MBSSID) and Enhanced
           MBSSID Advertisement (EMA) support in AP mode
         - support factory test mode
      - RealTek (rtw89):
         - add RSSI based antenna diversity
         - support U-NII-4 channels on 5 GHz band
      - RealTek (rtl8xxxu):
         - AP mode support for 8188f
         - support USB RX aggregation for the newer chips"

* tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1602 commits)
  net: scm: introduce and use scm_recv_unix helper
  af_unix: Skip SCM_PIDFD if scm->pid is NULL.
  net: lan743x: Simplify comparison
  netlink: Add __sock_i_ino() for __netlink_diag_dump().
  net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses
  Revert "af_unix: Call scm_recv() only after scm_set_cred()."
  phylink: ReST-ify the phylink_pcs_neg_mode() kdoc
  libceph: Partially revert changes to support MSG_SPLICE_PAGES
  net: phy: mscc: fix packet loss due to RGMII delays
  net: mana: use vmalloc_array and vcalloc
  net: enetc: use vmalloc_array and vcalloc
  ionic: use vmalloc_array and vcalloc
  pds_core: use vmalloc_array and vcalloc
  gve: use vmalloc_array and vcalloc
  octeon_ep: use vmalloc_array and vcalloc
  net: usb: qmi_wwan: add u-blox 0x1312 composition
  perf trace: fix MSG_SPLICE_PAGES build error
  ipvlan: Fix return value of ipvlan_queue_xmit()
  netfilter: nf_tables: fix underflow in chain reference counter
  netfilter: nf_tables: unbind non-anonymous set if rule construction fails
  ...
2023-06-28 16:43:10 -07:00
Linus Torvalds 6581ccf03e mm: fix __access_remote_vm() GUP failure case
Commit ca5e863233 ("mm/gup: remove vmas parameter from
get_user_pages_remote()") removed the vma argument from GUP handling,
and instead added a helper function (get_user_page_vma_remote()) that
looks it up separately using 'vma_lookup()'.  And then converted
existing users that needed a vma to use the helper instead.

However, the helper function intentionally acts exactly like the old
get_user_pages_remote() did, and only fills in 'vma' on successful page
lookup.  Fine so far.

However, __access_remote_vm() wants the vma even for the unsuccessful
case, and used to do a

	vma = vma_lookup(mm, addr);

explicitly to look it up when the get_user_page() failed.

However, that conversion commit incorrectly removed that vma lookup,
thinking that get_user_page_vma_remote() would have done it.  Not so.

So add the vma_lookup() back in.

Fixes: ca5e863233 ("mm/gup: remove vmas parameter from get_user_pages_remote()")
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-06-28 12:20:24 -07:00
Linus Torvalds 77b1a7f7a0 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in
top-level directories.
 
 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector.  It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs.
 
 - Zhen Lei has enhanced kexec's ability to support two crash regions.
 
 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries.
 
 - And the usual bunch of singleton patches in various places.
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Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...
2023-06-28 10:59:38 -07:00
Linus Torvalds 6e17c6de3d - Yosry Ahmed brought back some cgroup v1 stats in OOM logs.
- Yosry has also eliminated cgroup's atomic rstat flushing.
 
 - Nhat Pham adds the new cachestat() syscall.  It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability.
 
 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning.
 
 - Lorenzo Stoakes has done some maintanance work on the get_user_pages()
   interface.
 
 - Liam Howlett continues with cleanups and maintenance work to the maple
   tree code.  Peng Zhang also does some work on maple tree.
 
 - Johannes Weiner has done some cleanup work on the compaction code.
 
 - David Hildenbrand has contributed additional selftests for
   get_user_pages().
 
 - Thomas Gleixner has contributed some maintenance and optimization work
   for the vmalloc code.
 
 - Baolin Wang has provided some compaction cleanups,
 
 - SeongJae Park continues maintenance work on the DAMON code.
 
 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting.
 
 - Christoph Hellwig has some cleanups for the filemap/directio code.
 
 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the provided
   APIs rather than open-coding accesses.
 
 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings.
 
 - John Hubbard has a series of fixes to the MM selftesting code.
 
 - ZhangPeng continues the folio conversion campaign.
 
 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock.
 
 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from
   128 to 8.
 
 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management.
 
 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code.
 
 - Vishal Moola also has done some folio conversion work.
 
 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch.
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Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:

 - Yosry Ahmed brought back some cgroup v1 stats in OOM logs

 - Yosry has also eliminated cgroup's atomic rstat flushing

 - Nhat Pham adds the new cachestat() syscall. It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability

 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning

 - Lorenzo Stoakes has done some maintanance work on the
   get_user_pages() interface

 - Liam Howlett continues with cleanups and maintenance work to the
   maple tree code. Peng Zhang also does some work on maple tree

 - Johannes Weiner has done some cleanup work on the compaction code

 - David Hildenbrand has contributed additional selftests for
   get_user_pages()

 - Thomas Gleixner has contributed some maintenance and optimization
   work for the vmalloc code

 - Baolin Wang has provided some compaction cleanups,

 - SeongJae Park continues maintenance work on the DAMON code

 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting

 - Christoph Hellwig has some cleanups for the filemap/directio code

 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the
   provided APIs rather than open-coding accesses

 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings

 - John Hubbard has a series of fixes to the MM selftesting code

 - ZhangPeng continues the folio conversion campaign

 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock

 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
   from 128 to 8

 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management

 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code

 - Vishal Moola also has done some folio conversion work

 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch

* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
  mm/hugetlb: remove hugetlb_set_page_subpool()
  mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
  hugetlb: revert use of page_cache_next_miss()
  Revert "page cache: fix page_cache_next/prev_miss off by one"
  mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
  mm: memcg: rename and document global_reclaim()
  mm: kill [add|del]_page_to_lru_list()
  mm: compaction: convert to use a folio in isolate_migratepages_block()
  mm: zswap: fix double invalidate with exclusive loads
  mm: remove unnecessary pagevec includes
  mm: remove references to pagevec
  mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
  mm: remove struct pagevec
  net: convert sunrpc from pagevec to folio_batch
  i915: convert i915_gpu_error to use a folio_batch
  pagevec: rename fbatch_count()
  mm: remove check_move_unevictable_pages()
  drm: convert drm_gem_put_pages() to use a folio_batch
  i915: convert shmem_sg_free_table() to use a folio_batch
  scatterlist: add sg_set_folio()
  ...
2023-06-28 10:28:11 -07:00
David Woodhouse 6c26bd4384 mm/mmap: Fix error return in do_vmi_align_munmap()
If mas_store_gfp() in the gather loop failed, the 'error' variable that
ultimately gets returned was not being set. In many cases, its original
value of -ENOMEM was still in place, and that was fine. But if VMAs had
been split at the start or end of the range, then 'error' could be zero.

Change to the 'error = foo(); if (error) goto …' idiom to fix the bug.

Also clean up a later case which avoided the same bug by *explicitly*
setting error = -ENOMEM right before calling the function that might
return -ENOMEM.

In a final cosmetic change, move the 'Point of no return' comment to
*after* the goto. That's been in the wrong place since the preallocation
was removed, and this new error path was added.

Fixes: 606c812eb1 ("mm/mmap: Fix error path in do_vmi_align_munmap()")
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
2023-06-28 14:39:07 +01:00