WSL2-Linux-Kernel/mm
Peter Xu 3d2f78f08c mm/mprotect: only reference swap pfn page if type match
Yu Zhao reported a bug after the commit "mm/swap: Add swp_offset_pfn() to
fetch PFN from swap entry" added a check in swp_offset_pfn() for swap type [1]:

  kernel BUG at include/linux/swapops.h:117!
  CPU: 46 PID: 5245 Comm: EventManager_De Tainted: G S         O L 6.0.0-dbg-DEV #2
  RIP: 0010:pfn_swap_entry_to_page+0x72/0xf0
  Code: c6 48 8b 36 48 83 fe ff 74 53 48 01 d1 48 83 c1 08 48 8b 09 f6
  c1 01 75 7b 66 90 48 89 c1 48 8b 09 f6 c1 01 74 74 5d c3 eb 9e <0f> 0b
  48 ba ff ff ff ff 03 00 00 00 eb ae a9 ff 0f 00 00 75 13 48
  RSP: 0018:ffffa59e73fabb80 EFLAGS: 00010282
  RAX: 00000000ffffffe8 RBX: 0c00000000000000 RCX: ffffcd5440000000
  RDX: 1ffffffffff7a80a RSI: 0000000000000000 RDI: 0c0000000000042b
  RBP: ffffa59e73fabb80 R08: ffff9965ca6e8bb8 R09: 0000000000000000
  R10: ffffffffa5a2f62d R11: 0000030b372e9fff R12: ffff997b79db5738
  R13: 000000000000042b R14: 0c0000000000042b R15: 1ffffffffff7a80a
  FS:  00007f549d1bb700(0000) GS:ffff99d3cf680000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000440d035b3180 CR3: 0000002243176004 CR4: 00000000003706e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   <TASK>
   change_pte_range+0x36e/0x880
   change_p4d_range+0x2e8/0x670
   change_protection_range+0x14e/0x2c0
   mprotect_fixup+0x1ee/0x330
   do_mprotect_pkey+0x34c/0x440
   __x64_sys_mprotect+0x1d/0x30

It triggers because pfn_swap_entry_to_page() could be called upon e.g. a
genuine swap entry.

Fix it by only calling it when it's a write migration entry where the page*
is used.

[1] https://lore.kernel.org/lkml/CAOUHufaVC2Za-p8m0aiHw6YkheDcrO-C3wRGixwDS32VTS+k1w@mail.gmail.com/

Link: https://lkml.kernel.org/r/20220823221138.45602-1-peterx@redhat.com
Fixes: 6c287605fd ("mm: remember exclusively mapped anonymous pages with PG_anon_exclusive")
Signed-off-by: Peter Xu <peterx@redhat.com>
Reported-by: Yu Zhao <yuzhao@google.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28 14:02:46 -07:00
..
damon mm/damon/dbgfs: avoid duplicate context directory creation 2022-08-28 14:02:45 -07:00
kasan
kfence
Kconfig
Kconfig.debug
Makefile
backing-dev.c writeback: avoid use-after-free after removing device 2022-08-28 14:02:43 -07:00
balloon_compaction.c
bootmem_info.c bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem 2022-08-28 14:02:45 -07:00
cma.c
cma.h
cma_debug.c
cma_sysfs.c
compaction.c
debug.c
debug_page_ref.c
debug_vm_pgtable.c
dmapool.c
early_ioremap.c
fadvise.c
failslab.c
filemap.c
folio-compat.c
frontswap.c
gup.c mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW 2022-08-20 15:17:44 -07:00
gup_test.c
gup_test.h
highmem.c
hmm.c
huge_memory.c mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW 2022-08-20 15:17:44 -07:00
hugetlb.c mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte 2022-08-28 14:02:43 -07:00
hugetlb_cgroup.c
hugetlb_vmemmap.c
hugetlb_vmemmap.h
hwpoison-inject.c
init-mm.c
internal.h
interval_tree.c
io-mapping.c
ioremap.c
khugepaged.c
kmemleak.c
ksm.c
list_lru.c
maccess.c
madvise.c
mapping_dirty_helpers.c
memblock.c
memcontrol.c
memfd.c
memory-failure.c
memory.c
memory_hotplug.c
mempolicy.c
mempool.c
memremap.c
memtest.c
migrate.c
migrate_device.c
mincore.c
mlock.c
mm_init.c
mmap.c mm/hugetlb: fix hugetlb not supporting softdirty tracking 2022-08-20 15:17:45 -07:00
mmap_lock.c
mmu_gather.c
mmu_notifier.c
mmzone.c
mprotect.c mm/mprotect: only reference swap pfn page if type match 2022-08-28 14:02:46 -07:00
mremap.c
msync.c
nommu.c
oom_kill.c
page-writeback.c writeback: avoid use-after-free after removing device 2022-08-28 14:02:43 -07:00
page_alloc.c
page_counter.c
page_ext.c
page_idle.c
page_io.c
page_isolation.c
page_owner.c
page_poison.c
page_reporting.c
page_reporting.h
page_table_check.c
page_vma_mapped.c
pagewalk.c
percpu-internal.h
percpu-km.c
percpu-stats.c
percpu-vm.c
percpu.c
pgalloc-track.h
pgtable-generic.c
process_vm_access.c
ptdump.c
readahead.c
rmap.c
rodata_test.c
secretmem.c
shmem.c shmem: update folio if shmem_replace_page() updates the page 2022-08-28 14:02:43 -07:00
shrinker_debug.c
shuffle.c
shuffle.h
slab.c
slab.h
slab_common.c
slob.c
slub.c
sparse-vmemmap.c
sparse.c
swap.c
swap.h
swap_cgroup.c
swap_slots.c
swap_state.c
swapfile.c
truncate.c
usercopy.c
userfaultfd.c mm/uffd: reset write protection when unregister with wp-mode 2022-08-20 15:17:45 -07:00
util.c
vmacache.c
vmalloc.c
vmpressure.c
vmscan.c
vmstat.c mm: add DEVICE_ZONE to FOR_ALL_ZONES 2022-08-20 15:17:45 -07:00
workingset.c
z3fold.c
zbud.c
zpool.c
zsmalloc.c mm/zsmalloc: do not attempt to free IS_ERR handle 2022-08-28 14:02:44 -07:00
zswap.c