Граф коммитов

444 Коммитов

Автор SHA1 Сообщение Дата
Waiman Long 2685027fca cgroup/cpuset: Remove cpus_allowed/mems_allowed setup in cpuset_init_smp()
There are 3 places where the cpu and node masks of the top cpuset can
be initialized in the order they are executed:
 1) start_kernel -> cpuset_init()
 2) start_kernel -> cgroup_init() -> cpuset_bind()
 3) kernel_init_freeable() -> do_basic_setup() -> cpuset_init_smp()

The first cpuset_init() call just sets all the bits in the masks.
The second cpuset_bind() call sets cpus_allowed and mems_allowed to the
default v2 values. The third cpuset_init_smp() call sets them back to
v1 values.

For systems with cgroup v2 setup, cpuset_bind() is called once.  As a
result, cpu and memory node hot add may fail to update the cpu and node
masks of the top cpuset to include the newly added cpu or node in a
cgroup v2 environment.

For systems with cgroup v1 setup, cpuset_bind() is called again by
rebind_subsystem() when the v1 cpuset filesystem is mounted as shown
in the dmesg log below with an instrumented kernel.

  [    2.609781] cpuset_bind() called - v2 = 1
  [    3.079473] cpuset_init_smp() called
  [    7.103710] cpuset_bind() called - v2 = 0

smp_init() is called after the first two init functions.  So we don't
have a complete list of active cpus and memory nodes until later in
cpuset_init_smp() which is the right time to set up effective_cpus
and effective_mems.

To fix this cgroup v2 mask setup problem, the potentially incorrect
cpus_allowed & mems_allowed setting in cpuset_init_smp() are removed.
For cgroup v2 systems, the initial cpuset_bind() call will set the masks
correctly.  For cgroup v1 systems, the second call to cpuset_bind()
will do the right setup.

cc: stable@vger.kernel.org
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-05-05 08:57:00 -10:00
Linus Torvalds 266d17a8c0 Driver core changes for 5.18-rc1
Here is the set of driver core changes for 5.18-rc1.
 
 Not much here, primarily it was a bunch of cleanups and small updates:
 	- kobj_type cleanups for default_groups
 	- documentation updates
 	- firmware loader minor changes
 	- component common helper added and take advantage of it in many
 	  drivers (the largest part of this pull request).
 
 There will be a merge conflict in drivers/power/supply/ab8500_chargalg.c
 with your tree, the merge conflict should be easy (take all the
 changes).
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 -----BEGIN PGP SIGNATURE-----
 
 iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCYkG6PA8cZ3JlZ0Brcm9h
 aC5jb20ACgkQMUfUDdst+ylMFwCfSIyAU4oLEgj+/Rfmx4o45cAVIWMAnit3zbdU
 wUUCGqKcOnTJEcW6dMPh
 =1VVi
 -----END PGP SIGNATURE-----

Merge tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the set of driver core changes for 5.18-rc1.

  Not much here, primarily it was a bunch of cleanups and small updates:

   - kobj_type cleanups for default_groups

   - documentation updates

   - firmware loader minor changes

   - component common helper added and take advantage of it in many
     drivers (the largest part of this pull request).

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits)
  Documentation: update stable review cycle documentation
  drivers/base/dd.c : Remove the initial value of the global variable
  Documentation: update stable tree link
  Documentation: add link to stable release candidate tree
  devres: fix typos in comments
  Documentation: add note block surrounding security patch note
  samples/kobject: Use sysfs_emit instead of sprintf
  base: soc: Make soc_device_match() simpler and easier to read
  driver core: dd: fix return value of __setup handler
  driver core: Refactor sysfs and drv/bus remove hooks
  driver core: Refactor multiple copies of device cleanup
  scripts: get_abi.pl: Fix typo in help message
  kernfs: fix typos in comments
  kernfs: remove unneeded #if 0 guard
  ALSA: hda/realtek: Make use of the helper component_compare_dev_name
  video: omapfb: dss: Make use of the helper component_compare_dev
  power: supply: ab8500: Make use of the helper component_compare_dev
  ASoC: codecs: wcd938x: Make use of the helper component_compare/release_of
  iommu/mediatek: Make use of the helper component_compare/release_of
  drm: of: Make use of the helper component_release_of
  ...
2022-03-28 12:41:28 -07:00
Linus Torvalds 52deda9551 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "Various misc subsystems, before getting into the post-linux-next
  material.

  41 patches.

  Subsystems affected by this patch series: procfs, misc, core-kernel,
  lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump,
  taskstats, panic, kcov, resource, and ubsan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
  Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"
  kernel/resource: fix kfree() of bootmem memory again
  kcov: properly handle subsequent mmap calls
  kcov: split ioctl handling into locked and unlocked parts
  panic: move panic_print before kmsg dumpers
  panic: add option to dump all CPUs backtraces in panic_print
  docs: sysctl/kernel: add missing bit to panic_print
  taskstats: remove unneeded dead assignment
  kasan: no need to unset panic_on_warn in end_report()
  ubsan: no need to unset panic_on_warn in ubsan_epilogue()
  panic: unset panic_on_warn inside panic()
  docs: kdump: add scp example to write out the dump file
  docs: kdump: update description about sysfs file system support
  arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
  kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible
  cgroup: use irqsave in cgroup_rstat_flush_locked().
  fat: use pointer to simple type in put_user()
  minix: fix bug when opening a file with O_DIRECT
  ...
2022-03-24 14:14:07 -07:00
Sebastian Andrzej Siewior b1e2c8df0f cgroup: use irqsave in cgroup_rstat_flush_locked().
All callers of cgroup_rstat_flush_locked() acquire cgroup_rstat_lock
either with spin_lock_irq() or spin_lock_irqsave().
cgroup_rstat_flush_locked() itself acquires cgroup_rstat_cpu_lock which
is a raw_spin_lock.  This lock is also acquired in
cgroup_rstat_updated() in IRQ context and therefore requires _irqsave()
locking suffix in cgroup_rstat_flush_locked().

Since there is no difference between spin_lock_t and raw_spin_lock_t on
!RT lockdep does not complain here.  On RT lockdep complains because the
interrupts were not disabled here and a deadlock is possible.

Acquire the raw_spin_lock_t with disabled interrupts.

Link: https://lkml.kernel.org/r/20220301122143.1521823-2-bigeasy@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Subject: cgroup: add a comment to cgroup_rstat_flush_locked().

Add a comment why spin_lock_irq() -> raw_spin_lock_irqsave() is needed.

Link: https://lkml.kernel.org/r/Yh+DOK73hfVV5ThX@linutronix.de
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-23 19:00:34 -07:00
Linus Torvalds 2fce7ea0e0 Merge branch 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "All trivial cleanups without meaningful behavior changes"

* 'for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: cleanup comments
  cgroup: Fix cgroup_can_fork() and cgroup_post_fork() kernel-doc comment
  cgroup: rstat: retrieve current bstat to delta directly
  cgroup: rstat: use same convention to assign cgroup_base_stat
2022-03-23 12:43:35 -07:00
Ingo Molnar ccdbf33c23 Linux 5.17-rc8
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmIuUskeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGCFkH/2n3mpGXuITp0ZXE
 TNrpbdZOof5SgLw+w7THswXuo6m5yRGNKQs9fvIvDD8Vf7/OdQQfPOmF1cIE5+nk
 wcz6aHKbdrok8Jql2qjJqWXZ5xbGj6qywg3zZrwOUsCKFP5p+AjBJcmZOsvQHjSp
 ASODy1moOlK+nO52TrMaJw74a8xQPmQiNa+T2P+FedEYjlcRH/c7hLJ7GEnL6+cC
 /R4bATZq3tiInbTBlkC0hR0iVNgRXwXNyv9PEXrYYYHnekh8G1mgSNf06iejLcsG
 aAYsW9NyPxu8zPhhHNx79K9o8BMtxGD4YQpsfdfIEnf9Q3euqAKe2evRWqHHlDms
 RuSCtsc=
 =M9Nc
 -----END PGP SIGNATURE-----

Merge tag 'v5.17-rc8' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2022-03-15 10:28:12 +01:00
Tom Rix f9da322e86 cgroup: cleanup comments
for spdx, add a space before //

replacements
judgement to judgment
transofrmed to transformed
partitition to partition
histrical to historical
migratecd to migrated

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-03-13 19:19:27 -10:00
Greg Kroah-Hartman 4a248f85b3 Merge 5.17-rc6 into driver-core-next
We need the driver core fix in here as well for future changes.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-28 07:45:41 +01:00
Greg Kroah-Hartman f2eb478f2f kernfs: move struct kernfs_root out of the public view.
There is no need to have struct kernfs_root be part of kernfs.h for
the whole kernel to see and poke around it.  Move it internal to kernfs
code and provide a helper function, kernfs_root_to_node(), to handle the
one field that kernfs users were directly accessing from the structure.

Cc: Imran Khan <imran.f.khan@oracle.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220222070713.3517679-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-23 15:46:34 +01:00
Linus Torvalds 5c1ee56966 Merge branch 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:

 - Fix for a subtle bug in the recent release_agent permission check
   update

 - Fix for a long-standing race condition between cpuset and cpu hotplug

 - Comment updates

* 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: Fix kernel-doc
  cgroup-v1: Correct privileges check in release_agent writes
  cgroup: clarify cgroup_css_set_fork()
  cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug
2022-02-22 16:14:35 -08:00
Jiapeng Chong c70cd039f1 cpuset: Fix kernel-doc
Fix the following W=1 kernel warnings:

kernel/cgroup/cpuset.c:3718: warning: expecting prototype for
cpuset_memory_pressure_bump(). Prototype was for
__cpuset_memory_pressure_bump() instead.

kernel/cgroup/cpuset.c:3568: warning: expecting prototype for
cpuset_node_allowed(). Prototype was for __cpuset_node_allowed()
instead.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-22 09:49:49 -10:00
Michal Koutný 467a726b75 cgroup-v1: Correct privileges check in release_agent writes
The idea is to check: a) the owning user_ns of cgroup_ns, b)
capabilities in init_user_ns.

The commit 24f6008564 ("cgroup-v1: Require capabilities to set
release_agent") got this wrong in the write handler of release_agent
since it checked user_ns of the opener (may be different from the owning
user_ns of cgroup_ns).
Secondly, to avoid possibly confused deputy, the capability of the
opener must be checked.

Fixes: 24f6008564 ("cgroup-v1: Require capabilities to set release_agent")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/stable/20220216121142.GB30035@blackbody.suse.cz/
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Masami Ichikawa(CIP) <masami.ichikawa@cybertrust.co.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-22 08:12:22 -10:00
Christian Brauner 6d3971dab2 cgroup: clarify cgroup_css_set_fork()
With recent fixes for the permission checking when moving a task into a cgroup
using a file descriptor to a cgroup's cgroup.procs file and calling write() it
seems a good idea to clarify CLONE_INTO_CGROUP permission checking with a
comment.

Cc: Tejun Heo <tj@kernel.org>
Cc: <cgroups@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-22 07:35:19 -10:00
Ingo Molnar 6255b48aeb Linux 5.17-rc5
-----BEGIN PGP SIGNATURE-----
 
 iQFSBAABCAA8FiEEq68RxlopcLEwq+PEeb4+QwBBGIYFAmISrYgeHHRvcnZhbGRz
 QGxpbnV4LWZvdW5kYXRpb24ub3JnAAoJEHm+PkMAQRiGg20IAKDZr7rfSHBopjQV
 Cocw744tom0XuxpvSZpp2GGOOXF+tkswcNNaRIrbGOl1mkyxA7eBZCTMpDeDS9aQ
 wB0D0Gxx8QBAJp4KgB1W7TB+hIGes/rs8Ve+6iO4ulLLdCVWX/q2boI0aZ7QX9O9
 qNi8OsoZQtk6falRvciZFHwV5Av1p2Sy1AW57udQ7DvJ4H98AfKf1u8/z208WWW8
 1ixC+qJxQcUcM9vI+7P9Tt7NbFSKv8SvAmqjFY7P+DxQAsVw6KXoqVXykDzeOv0t
 fUNOE/t0oFZafwtn8h7KBQnwS9lH03+3KkslVZs+iMFyUj/Bar+NVVyKoDhWXtVg
 /PuMhEg=
 =eU1o
 -----END PGP SIGNATURE-----

Merge tag 'v5.17-rc5' into sched/core, to resolve conflicts

New conflicts in sched/core due to the following upstream fixes:

  44585f7bc0 ("psi: fix "defined but not used" warnings when CONFIG_PROC_FS=n")
  a06247c680 ("psi: Fix uaf issue when psi trigger is destroyed while being polled")

Conflicts:
	include/linux/psi_types.h
	kernel/sched/psi.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2022-02-21 11:53:51 +01:00
Frederic Weisbecker 04d4e665a6 sched/isolation: Use single feature type while referring to housekeeping cpumask
Refer to housekeeping APIs using single feature types instead of flags.
This prevents from passing multiple isolation features at once to
housekeeping interfaces, which soon won't be possible anymore as each
isolation features will have their own cpumask.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
2022-02-16 15:57:55 +01:00
Zhang Qiao 05c7b7a92c cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug
As previously discussed(https://lkml.org/lkml/2022/1/20/51),
cpuset_attach() is affected with similar cpu hotplug race,
as follow scenario:

     cpuset_attach()				cpu hotplug
    ---------------------------            ----------------------
    down_write(cpuset_rwsem)
    guarantee_online_cpus() // (load cpus_attach)
					sched_cpu_deactivate
					  set_cpu_active()
					  // will change cpu_active_mask
    set_cpus_allowed_ptr(cpus_attach)
      __set_cpus_allowed_ptr_locked()
       // (if the intersection of cpus_attach and
         cpu_active_mask is empty, will return -EINVAL)
    up_write(cpuset_rwsem)

To avoid races such as described above, protect cpuset_attach() call
with cpu_hotplug_lock.

Fixes: be367d0992 ("cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time")
Cc: stable@vger.kernel.org # v2.6.32+
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-14 09:48:04 -10:00
Linus Torvalds 305e6c42e8 Merge branch 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:

 - Eric's fix for a long standing cgroup1 permission issue where it only
   checks for uid 0 instead of CAP which inadvertently allows
   unprivileged userns roots to modify release_agent userhelper

 - Fixes for the fallout from Waiman's recent cpuset work

* 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup/cpuset: Fix "suspicious RCU usage" lockdep warning
  cgroup-v1: Require capabilities to set release_agent
  cpuset: Fix the bug that subpart_cpus updated wrongly in update_cpumask()
  cgroup/cpuset: Make child cpusets restrict parents on v1 hierarchy
2022-02-03 08:15:13 -08:00
Waiman Long 2bdfd2825c cgroup/cpuset: Fix "suspicious RCU usage" lockdep warning
It was found that a "suspicious RCU usage" lockdep warning was issued
with the rcu_read_lock() call in update_sibling_cpumasks().  It is
because the update_cpumasks_hier() function may sleep. So we have
to release the RCU lock, call update_cpumasks_hier() and reacquire
it afterward.

Also add a percpu_rwsem_assert_held() in update_sibling_cpumasks()
instead of stating that in the comment.

Fixes: 4716909cc5 ("cpuset: Track cpusets that use parent's effective_cpus")
Signed-off-by: Waiman Long <longman@redhat.com>
Tested-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-03 05:59:01 -10:00
Eric W. Biederman 24f6008564 cgroup-v1: Require capabilities to set release_agent
The cgroup release_agent is called with call_usermodehelper.  The function
call_usermodehelper starts the release_agent with a full set fo capabilities.
Therefore require capabilities when setting the release_agaent.

Reported-by: Tabitha Sable <tabitha.c.sable@gmail.com>
Tested-by: Tabitha Sable <tabitha.c.sable@gmail.com>
Fixes: 81a6a5cdd2 ("Task Control Groups: automatic userspace notification of idle cgroups")
Cc: stable@vger.kernel.org # v2.6.24+
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-02-01 07:28:00 -10:00
Tianchen Ding c80d401c52 cpuset: Fix the bug that subpart_cpus updated wrongly in update_cpumask()
subparts_cpus should be limited as a subset of cpus_allowed, but it is
updated wrongly by using cpumask_andnot(). Use cpumask_and() instead to
fix it.

Fixes: ee8dde0cd2 ("cpuset: Add new v2 cpuset.sched.partition flag")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-26 06:49:30 -10:00
Suren Baghdasaryan a06247c680 psi: Fix uaf issue when psi trigger is destroyed while being polled
With write operation on psi files replacing old trigger with a new one,
the lifetime of its waitqueue is totally arbitrary. Overwriting an
existing trigger causes its waitqueue to be freed and pending poll()
will stumble on trigger->event_wait which was destroyed.
Fix this by disallowing to redefine an existing psi trigger. If a write
operation is used on a file descriptor with an already existing psi
trigger, the operation will fail with EBUSY error.
Also bypass a check for psi_disabled in the psi_trigger_destroy as the
flag can be flipped after the trigger is created, leading to a memory
leak.

Fixes: 0e94682b73 ("psi: introduce psi monitor")
Reported-by: syzbot+cdb5dd11c97cc532efad@syzkaller.appspotmail.com
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Analyzed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20220111232309.1786347-1-surenb@google.com
2022-01-18 12:09:57 +01:00
Michal Koutný d068eebbd4 cgroup/cpuset: Make child cpusets restrict parents on v1 hierarchy
The commit 1f1562fcd0 ("cgroup/cpuset: Don't let child cpusets
restrict parent in default hierarchy") inteded to relax the check only
on the default hierarchy (or v2 mode) but it dropped the check in v1
too.

This patch returns and separates the legacy-only validations so that
they can be considered only in the v1 mode, which should enforce the old
constraints for the sake of compatibility.

Fixes: 1f1562fcd0 ("cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy")
Suggested-by: Waiman Long <longman@redhat.com>
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-12 11:24:45 -10:00
Yang Li ffacbd11e2 cgroup: Fix cgroup_can_fork() and cgroup_post_fork() kernel-doc comment
Add the description of @kargs in cgroup_can_fork() and
cgroup_post_fork() kernel-doc comment to remove warnings found
by running scripts/kernel-doc, which is caused by using 'make W=1'.

kernel/cgroup/cgroup.c:6235: warning: Function parameter or member
'kargs' not described in 'cgroup_can_fork'
kernel/cgroup/cgroup.c:6296: warning: Function parameter or member
'kargs' not described in 'cgroup_post_fork'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-12 09:55:25 -10:00
Wei Yang 95b99f353c cgroup: rstat: retrieve current bstat to delta directly
Instead of retrieve current bstat to cur and copy it to delta, let's use
delta directly.

This saves one copy operation and has the same code convention as
propagating delta to parent.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-12 09:55:12 -10:00
Wei Yang 4148be7de0 cgroup: rstat: use same convention to assign cgroup_base_stat
In function cgroup_base_stat_flush(), we update cgroup_base_stat by
getting rstatc->bstat and adjust delta to related fields.

There are two convention to assign cgroup_base_stat in this function:

  * rstat2 = rstat1
  * rstat2.cputime = rstat1.cputime

The second convention may make audience think just field "cputime" is
updated, while cputime is the only field in cgroup_base_stat.

Let's use the same convention to eliminate this confusion.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-12 09:55:02 -10:00
Linus Torvalds ea1ca66d3c Merge branch 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "Nothing too interesting. The only two noticeable changes are a subtle
  cpuset behavior fix and trace event id field being expanded to u64
  from int. Most others are code cleanups"

* 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean
  cgroup/rstat: check updated_next only for root
  cgroup: rstat: explicitly put loop variant in while
  cgroup: return early if it is already on preloaded list
  cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy
  cgroup: Trace event cgroup id fields should be u64
  cgroup: fix a typo in comment
  cgroup: get the wrong css for css_alloc() during cgroup_init_subsys()
  cgroup: rstat: Mark benign data race to silence KCSAN
2022-01-11 09:14:37 -08:00
Linus Torvalds 8efd0d9c31 Networking changes for 5.17.
Core
 ----
 
  - Defer freeing TCP skbs to the BH handler, whenever possible,
    or at least perform the freeing outside of the socket lock section
    to decrease cross-CPU allocator work and improve latency.
 
  - Add netdevice refcount tracking to locate sources of netdevice
    and net namespace refcount leaks.
 
  - Make Tx watchdog less intrusive - avoid pausing Tx and restarting
    all queues from a single CPU removing latency spikes.
 
  - Various small optimizations throughout the stack from Eric Dumazet.
 
  - Make netdev->dev_addr[] constant, force modifications to go via
    appropriate helpers to allow us to keep addresses in ordered data
    structures.
 
  - Replace unix_table_lock with per-hash locks, improving performance
    of bind() calls.
 
  - Extend skb drop tracepoint with a drop reason.
 
  - Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.
 
 BPF
 ---
 
  - New helpers:
    - bpf_find_vma(), find and inspect VMAs for profiling use cases
    - bpf_loop(), runtime-bounded loop helper trading some execution
      time for much faster (if at all converging) verification
    - bpf_strncmp(), improve performance, avoid compiler flakiness
    - bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
      for tracing programs, all inlined by the verifier
 
  - Support BPF relocations (CO-RE) in the kernel loader.
 
  - Further the support for BTF_TYPE_TAG annotations.
 
  - Allow access to local storage in sleepable helpers.
 
  - Convert verifier argument types to a composable form with different
    attributes which can be shared across types (ro, maybe-null).
 
  - Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
    creating new, extensible ones where missing and deprecating those
    to be removed.
 
 Protocols
 ---------
 
  - WiFi (mac80211/cfg80211):
    - notify user space about long "come back in N" AP responses,
      allow it to react to such temporary rejections
    - allow non-standard VHT MCS 10/11 rates
    - use coarse time in airtime fairness code to save CPU cycles
 
  - Bluetooth:
    - rework of HCI command execution serialization to use a common
      queue and work struct, and improve handling errors reported
      in the middle of a batch of commands
    - rework HCI event handling to use skb_pull_data, avoiding packet
      parsing pitfalls
    - support AOSP Bluetooth Quality Report
 
  - SMC:
    - support net namespaces, following the RDMA model
    - improve connection establishment latency by pre-clearing buffers
    - introduce TCP ULP for automatic redirection to SMC
 
  - Multi-Path TCP:
    - support ioctls: SIOCINQ, OUTQ, and OUTQNSD
    - support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
      IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
    - support cmsgs: TCP_INQ
    - improvements in the data scheduler (assigning data to subflows)
    - support fastclose option (quick shutdown of the full MPTCP
      connection, similar to TCP RST in regular TCP)
 
  - MCTP (Management Component Transport) over serial, as defined by
    DMTF spec DSP0253 - "MCTP Serial Transport Binding".
 
 Driver API
 ----------
 
  - Support timestamping on bond interfaces in active/passive mode.
 
  - Introduce generic phylink link mode validation for drivers which
    don't have any quirks and where MAC capability bits fully express
    what's supported. Allow PCS layer to participate in the validation.
    Convert a number of drivers.
 
  - Add support to set/get size of buffers on the Rx rings and size of
    the tx copybreak buffer via ethtool.
 
  - Support offloading TC actions as first-class citizens rather than
    only as attributes of filters, improve sharing and device resource
    utilization.
 
  - WiFi (mac80211/cfg80211):
    - support forwarding offload (ndo_fill_forward_path)
    - support for background radar detection hardware
    - SA Query Procedures offload on the AP side
 
 New hardware / drivers
 ----------------------
 
  - tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
    real-time requirements for isochronous communication with protocols
    like OPC UA Pub/Sub.
 
  - Qualcomm BAM-DMUX WWAN - driver for data channels of modems
    integrated into many older Qualcomm SoCs, e.g. MSM8916 or
    MSM8974 (qcom_bam_dmux).
 
  - Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch
    driver with support for bridging, VLANs and multicast forwarding
    (lan966x).
 
  - iwlmei driver for co-operating between Intel's WiFi driver and
    Intel's Active Management Technology (AMT) devices.
 
  - mse102x - Vertexcom MSE102x Homeplug GreenPHY chips
 
  - Bluetooth:
    - MediaTek MT7921 SDIO devices
    - Foxconn MT7922A
    - Realtek RTL8852AE
 
 Drivers
 -------
 
  - Significantly improve performance in the datapaths of:
    lan78xx, ax88179_178a, lantiq_xrx200, bnxt.
 
  - Intel Ethernet NICs:
    - igb: support PTP/time PEROUT and EXTTS SDP functions on
      82580/i354/i350 adapters
    - ixgbevf: new PF -> VF mailbox API which avoids the risk of
      mailbox corruption with ESXi
    - iavf: support configuration of VLAN features of finer granularity,
      stacked tags and filtering
    - ice: PTP support for new E822 devices with sub-ns precision
    - ice: support firmware activation without reboot
 
  - Mellanox Ethernet NICs (mlx5):
    - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
    - support TC forwarding when tunnel encap and decap happen between
      two ports of the same NIC
    - dynamically size and allow disabling various features to save
      resources for running in embedded / SmartNIC scenarios
 
  - Broadcom Ethernet NICs (bnxt):
    - use page frag allocator to improve Rx performance
    - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
 
  - Other Ethernet NICs:
    - amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support
 
  - Microsoft cloud/virtual NIC (mana):
    - add XDP support (PASS, DROP, TX)
 
  - Mellanox Ethernet switches (mlxsw):
    - initial support for Spectrum-4 ASICs
    - VxLAN with IPv6 underlay
 
  - Marvell Ethernet switches (prestera):
    - support flower flow templates
    - add basic IP forwarding support
 
  - NXP embedded Ethernet switches (ocelot & felix):
    - support Per-Stream Filtering and Policing (PSFP)
    - enable cut-through forwarding between ports by default
    - support FDMA to improve packet Rx/Tx to CPU
 
  - Other embedded switches:
    - hellcreek: improve trapping management (STP and PTP) packets
    - qca8k: support link aggregation and port mirroring
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - qca6390, wcn6855: enable 802.11 power save mode in station mode
    - BSS color change support
    - WCN6855 hw2.1 support
    - 11d scan offload support
    - scan MAC address randomization support
    - full monitor mode, only supported on QCN9074
    - qca6390/wcn6855: report signal and tx bitrate
    - qca6390: rfkill support
    - qca6390/wcn6855: regdb.bin support
 
  - Intel WiFi (iwlwifi):
    - support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
      in cooperation with the BIOS
    - support for Optimized Connectivity Experience (OCE) scan
    - support firmware API version 68
    - lots of preparatory work for the upcoming Bz device family
 
  - MediaTek WiFi (mt76):
    - Specific Absorption Rate (SAR) support
    - mt7921: 160 MHz channel support
 
  - RealTek WiFi (rtw88):
    - Specific Absorption Rate (SAR) support
    - scan offload
 
  - Other WiFi NICs
    - ath10k: support fetching (pre-)calibration data from nvmem
    - brcmfmac: configure keep-alive packet on suspend
    - wcn36xx: beacon filter support
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmHbkZAACgkQMUZtbf5S
 IruYkQ//XX7BggcwBfukPK83j0dONolClijqKcKR08g4vB5L8GXvv6OErKIWrh4k
 h8JanCH352ZkbCSw3MvFdm825UYQv8vPMd6Qks/LJ4aSKqCuy4MIlAo+yOw4Km3O
 i7++lRfma6DqHHI59wvLjWoxZSPu8lL+rI8UsZ5qMOlnNlGAOXsNrzRjaqQ3FddY
 AMxZeBUtrPqUCCQZFq3U8apkYzUp7CA/3XR9zRcja3uPbrtOV2G+4whRF90qGNWz
 Tm/QvJ9F/Ab292cbhxR4KuaQ3hUhaCQyDjbZk3+FZzZpAVhYTVqcNjny6+yXmbiP
 NXRtwemnl1NlWKMnJM8lEeY48u626tRIkxA/Wtd61uoO5uKUSxfGP+UpUi+DfXbF
 yIw50VQ7L2bpxXP/HjtmhVgZDaWKYyh22Zw4Hp/muMJz0hgUB0KODY3tf2jUWbjJ
 0oEgocWyzhhwMQKqupTDCIaRgIs2ewYr4ZrFDhI3HnHC/vv1VjoPRUPIyxwppD2N
 cXvZb3B1sWK8iX5gCbISGzyU4bB7I0rvJSTU42ueti7n6NqRFZ79qHQpYnnY+JdO
 z1qOwY/d/yWfBoXVKRtRg2qz6CdEt5BQklwAgVEBgrFpf58gp694EwGMb1htY14J
 r/k9bVpmyIFpUnBH2CPMRfBVA3tUTqzyzzFV4AMw40NYLKmhLdo=
 =KLm3
 -----END PGP SIGNATURE-----

Merge tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "Core
  ----

   - Defer freeing TCP skbs to the BH handler, whenever possible, or at
     least perform the freeing outside of the socket lock section to
     decrease cross-CPU allocator work and improve latency.

   - Add netdevice refcount tracking to locate sources of netdevice and
     net namespace refcount leaks.

   - Make Tx watchdog less intrusive - avoid pausing Tx and restarting
     all queues from a single CPU removing latency spikes.

   - Various small optimizations throughout the stack from Eric Dumazet.

   - Make netdev->dev_addr[] constant, force modifications to go via
     appropriate helpers to allow us to keep addresses in ordered data
     structures.

   - Replace unix_table_lock with per-hash locks, improving performance
     of bind() calls.

   - Extend skb drop tracepoint with a drop reason.

   - Allow SO_MARK and SO_PRIORITY setsockopt under CAP_NET_RAW.

  BPF
  ---

   - New helpers:
      - bpf_find_vma(), find and inspect VMAs for profiling use cases
      - bpf_loop(), runtime-bounded loop helper trading some execution
        time for much faster (if at all converging) verification
      - bpf_strncmp(), improve performance, avoid compiler flakiness
      - bpf_get_func_arg(), bpf_get_func_ret(), bpf_get_func_arg_cnt()
        for tracing programs, all inlined by the verifier

   - Support BPF relocations (CO-RE) in the kernel loader.

   - Further the support for BTF_TYPE_TAG annotations.

   - Allow access to local storage in sleepable helpers.

   - Convert verifier argument types to a composable form with different
     attributes which can be shared across types (ro, maybe-null).

   - Prepare libbpf for upcoming v1.0 release by cleaning up APIs,
     creating new, extensible ones where missing and deprecating those
     to be removed.

  Protocols
  ---------

   - WiFi (mac80211/cfg80211):
      - notify user space about long "come back in N" AP responses,
        allow it to react to such temporary rejections
      - allow non-standard VHT MCS 10/11 rates
      - use coarse time in airtime fairness code to save CPU cycles

   - Bluetooth:
      - rework of HCI command execution serialization to use a common
        queue and work struct, and improve handling errors reported in
        the middle of a batch of commands
      - rework HCI event handling to use skb_pull_data, avoiding packet
        parsing pitfalls
      - support AOSP Bluetooth Quality Report

   - SMC:
      - support net namespaces, following the RDMA model
      - improve connection establishment latency by pre-clearing buffers
      - introduce TCP ULP for automatic redirection to SMC

   - Multi-Path TCP:
      - support ioctls: SIOCINQ, OUTQ, and OUTQNSD
      - support socket options: IP_TOS, IP_FREEBIND, IP_TRANSPARENT,
        IPV6_FREEBIND, and IPV6_TRANSPARENT, TCP_CORK and TCP_NODELAY
      - support cmsgs: TCP_INQ
      - improvements in the data scheduler (assigning data to subflows)
      - support fastclose option (quick shutdown of the full MPTCP
        connection, similar to TCP RST in regular TCP)

   - MCTP (Management Component Transport) over serial, as defined by
     DMTF spec DSP0253 - "MCTP Serial Transport Binding".

  Driver API
  ----------

   - Support timestamping on bond interfaces in active/passive mode.

   - Introduce generic phylink link mode validation for drivers which
     don't have any quirks and where MAC capability bits fully express
     what's supported. Allow PCS layer to participate in the validation.
     Convert a number of drivers.

   - Add support to set/get size of buffers on the Rx rings and size of
     the tx copybreak buffer via ethtool.

   - Support offloading TC actions as first-class citizens rather than
     only as attributes of filters, improve sharing and device resource
     utilization.

   - WiFi (mac80211/cfg80211):
      - support forwarding offload (ndo_fill_forward_path)
      - support for background radar detection hardware
      - SA Query Procedures offload on the AP side

  New hardware / drivers
  ----------------------

   - tsnep - FPGA based TSN endpoint Ethernet MAC used in PLCs with
     real-time requirements for isochronous communication with protocols
     like OPC UA Pub/Sub.

   - Qualcomm BAM-DMUX WWAN - driver for data channels of modems
     integrated into many older Qualcomm SoCs, e.g. MSM8916 or MSM8974
     (qcom_bam_dmux).

   - Microchip LAN966x multi-port Gigabit AVB/TSN Ethernet Switch driver
     with support for bridging, VLANs and multicast forwarding
     (lan966x).

   - iwlmei driver for co-operating between Intel's WiFi driver and
     Intel's Active Management Technology (AMT) devices.

   - mse102x - Vertexcom MSE102x Homeplug GreenPHY chips

   - Bluetooth:
      - MediaTek MT7921 SDIO devices
      - Foxconn MT7922A
      - Realtek RTL8852AE

  Drivers
  -------

   - Significantly improve performance in the datapaths of: lan78xx,
     ax88179_178a, lantiq_xrx200, bnxt.

   - Intel Ethernet NICs:
      - igb: support PTP/time PEROUT and EXTTS SDP functions on
        82580/i354/i350 adapters
      - ixgbevf: new PF -> VF mailbox API which avoids the risk of
        mailbox corruption with ESXi
      - iavf: support configuration of VLAN features of finer
        granularity, stacked tags and filtering
      - ice: PTP support for new E822 devices with sub-ns precision
      - ice: support firmware activation without reboot

   - Mellanox Ethernet NICs (mlx5):
      - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool
      - support TC forwarding when tunnel encap and decap happen between
        two ports of the same NIC
      - dynamically size and allow disabling various features to save
        resources for running in embedded / SmartNIC scenarios

   - Broadcom Ethernet NICs (bnxt):
      - use page frag allocator to improve Rx performance
      - expose control over IRQ coalescing mode (CQE vs EQE) via ethtool

   - Other Ethernet NICs:
      - amd-xgbe: add Ryzen 6000 (Yellow Carp) Ethernet support

   - Microsoft cloud/virtual NIC (mana):
      - add XDP support (PASS, DROP, TX)

   - Mellanox Ethernet switches (mlxsw):
      - initial support for Spectrum-4 ASICs
      - VxLAN with IPv6 underlay

   - Marvell Ethernet switches (prestera):
      - support flower flow templates
      - add basic IP forwarding support

   - NXP embedded Ethernet switches (ocelot & felix):
      - support Per-Stream Filtering and Policing (PSFP)
      - enable cut-through forwarding between ports by default
      - support FDMA to improve packet Rx/Tx to CPU

   - Other embedded switches:
      - hellcreek: improve trapping management (STP and PTP) packets
      - qca8k: support link aggregation and port mirroring

   - Qualcomm 802.11ax WiFi (ath11k):
      - qca6390, wcn6855: enable 802.11 power save mode in station mode
      - BSS color change support
      - WCN6855 hw2.1 support
      - 11d scan offload support
      - scan MAC address randomization support
      - full monitor mode, only supported on QCN9074
      - qca6390/wcn6855: report signal and tx bitrate
      - qca6390: rfkill support
      - qca6390/wcn6855: regdb.bin support

   - Intel WiFi (iwlwifi):
      - support SAR GEO Offset Mapping (SGOM) and Time-Aware-SAR (TAS)
        in cooperation with the BIOS
      - support for Optimized Connectivity Experience (OCE) scan
      - support firmware API version 68
      - lots of preparatory work for the upcoming Bz device family

   - MediaTek WiFi (mt76):
      - Specific Absorption Rate (SAR) support
      - mt7921: 160 MHz channel support

   - RealTek WiFi (rtw88):
      - Specific Absorption Rate (SAR) support
      - scan offload

   - Other WiFi NICs
      - ath10k: support fetching (pre-)calibration data from nvmem
      - brcmfmac: configure keep-alive packet on suspend
      - wcn36xx: beacon filter support"

* tag '5.17-net-next' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2048 commits)
  tcp: tcp_send_challenge_ack delete useless param `skb`
  net/qla3xxx: Remove useless DMA-32 fallback configuration
  rocker: Remove useless DMA-32 fallback configuration
  hinic: Remove useless DMA-32 fallback configuration
  lan743x: Remove useless DMA-32 fallback configuration
  net: enetc: Remove useless DMA-32 fallback configuration
  cxgb4vf: Remove useless DMA-32 fallback configuration
  cxgb4: Remove useless DMA-32 fallback configuration
  cxgb3: Remove useless DMA-32 fallback configuration
  bnx2x: Remove useless DMA-32 fallback configuration
  et131x: Remove useless DMA-32 fallback configuration
  be2net: Remove useless DMA-32 fallback configuration
  vmxnet3: Remove useless DMA-32 fallback configuration
  bna: Simplify DMA setting
  net: alteon: Simplify DMA setting
  myri10ge: Simplify DMA setting
  qlcnic: Simplify DMA setting
  net: allwinner: Fix print format
  page_pool: remove spinlock in page_pool_refill_alloc_cache()
  amt: fix wrong return type of amt_send_membership_update()
  ...
2022-01-10 19:06:09 -08:00
Qi Zheng d4296faebd cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean
Convert 'allowed' in __cpuset_node_allowed() to be boolean since the
return types of node_isset() and __cpuset_node_allowed() are both
boolean.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-07 12:05:52 -10:00
Wei Yang f5f60d235e cgroup/rstat: check updated_next only for root
After commit dc26532aed ("cgroup: rstat: punt root-level optimization to
individual controllers"), each rstat on updated_children list has its
->updated_next not NULL.

This means we can remove the check on ->updated_next, if we make sure
the subtree from @root is on list, which could be done by checking
updated_next for root.

tj: Coding style fixes.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:50:34 -10:00
Wei Yang 0da41f7348 cgroup: rstat: explicitly put loop variant in while
Instead of do while unconditionally, let's put the loop variant in
while.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:10:06 -10:00
Tejun Heo e574576416 cgroup: Use open-time cgroup namespace for process migration perm checks
cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's cgroup namespace which is
a potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes cgroup remember the cgroup namespace at the time of open
and uses it for migration permission checks instad of current's. Note that
this only applies to cgroup2 as cgroup1 doesn't have namespace support.

This also fixes a use-after-free bug on cgroupns reported in

 https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com

Note that backporting this fix also requires the preceding patch.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reported-by: syzbot+50f5cf33a284ce738b62@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/00000000000048c15c05d0083397@google.com
Fixes: 5136f6365c ("cgroup: implement "nsdelegate" mount option")
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:02:29 -10:00
Tejun Heo 0d2b5955b3 cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv
of->priv is currently used by each interface file implementation to store
private information. This patch collects the current two private data usages
into struct cgroup_file_ctx which is allocated and freed by the common path.
This allows generic private data which applies to multiple files, which will
be used to in the following patch.

Note that cgroup_procs iterator is now embedded as procs.iter in the new
cgroup_file_ctx so that it doesn't need to be allocated and freed
separately.

v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in
    cgroup_file_ctx as suggested by Linus.

v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too.
    Converted. Didn't change to embedded allocation as cgroup1 pidlists get
    stored for caching.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
2022-01-06 11:02:29 -10:00
Tejun Heo 1756d7994a cgroup: Use open-time credentials for process migraton perm checks
cgroup process migration permission checks are performed at write time as
whether a given operation is allowed or not is dependent on the content of
the write - the PID. This currently uses current's credentials which is a
potential security weakness as it may allow scenarios where a less
privileged process tricks a more privileged one into writing into a fd that
it created.

This patch makes both cgroup2 and cgroup1 process migration interfaces to
use the credentials saved at the time of open (file->f_cred) instead of
current's.

Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Fixes: 187fe84067 ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy")
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2022-01-06 11:02:28 -10:00
Jakub Kicinski aef2feda97 add missing bpf-cgroup.h includes
We're about to break the cgroup-defs.h -> bpf-cgroup.h dependency,
make sure those who actually need more than the definition of
struct cgroup_bpf include bpf-cgroup.h explicitly.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20211216025538.1649516-3-kuba@kernel.org
2021-12-16 14:57:09 -08:00
Wei Yang 1815775e74 cgroup: return early if it is already on preloaded list
If a cset is already on preloaded list, this means we have already setup
this cset properly for migration.

This patch just relocates the root cgrp lookup which isn't used anyway
when the cset is already on the preloaded list.

[tj@kernel.org: rephrase the commit log]

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-14 09:45:20 -10:00
Waiman Long 1f1562fcd0 cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy
In validate_change(), there is a check since v2.6.12 to make sure that
each of the child cpusets must be a subset of a parent cpuset.  IOW, it
allows child cpusets to restrict what changes can be made to a parent's
"cpuset.cpus". This actually violates one of the core principles of the
default hierarchy where a cgroup higher up in the hierarchy should be
able to change configuration however it sees fit as deligation breaks
down otherwise.

To address this issue, the check is now removed for the default hierarchy
to free parent cpusets from being restricted by child cpusets. The
check will still apply for legacy hierarchy.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-12-13 10:41:02 -10:00
Wei Yang 8291471ea5 cgroup: get the wrong css for css_alloc() during cgroup_init_subsys()
css_alloc() needs the parent css, while cgroup_css() gets current
cgropu's css. So we are getting the wrong css during
cgroup_init_subsys().

Fortunately, cgrp_dfl_root.cgrp's css is not set yet, so the value we
pass to css_alloc() is NULL anyway.

Let's pass NULL directly during init, since we know there is no parent
yet.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-11-29 07:39:01 -10:00
Michal Koutný eda09706b2 cgroup: rstat: Mark benign data race to silence KCSAN
There is a race between updaters and flushers (flush can possibly miss
the latest update(s)). This is expected as explained in
cgroup_rstat_updated() comment, add also machine readable annotation so
that KCSAN results aren't noisy.

Reported-by: Hao Sun <sunhao.th@gmail.com>
Link: https://lore.kernel.org/r/CACkBjsbPVdkub=e-E-p1WBOLxS515ith-53SFdmFHWV_QMo40w@mail.gmail.com
Suggested-by: Hao Sun <sunhao.th@gmail.com>

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-11-15 11:34:17 -10:00
Linus Torvalds 512b7931ad Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "257 patches.

  Subsystems affected by this patch series: scripts, ocfs2, vfs, and
  mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
  gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
  pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
  memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
  vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
  cleanups, kfence, and damon)"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
  mm/damon: remove return value from before_terminate callback
  mm/damon: fix a few spelling mistakes in comments and a pr_debug message
  mm/damon: simplify stop mechanism
  Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
  Docs/admin-guide/mm/damon/start: simplify the content
  Docs/admin-guide/mm/damon/start: fix a wrong link
  Docs/admin-guide/mm/damon/start: fix wrong example commands
  mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
  mm/damon: remove unnecessary variable initialization
  Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
  mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
  selftests/damon: support watermarks
  mm/damon/dbgfs: support watermarks
  mm/damon/schemes: activate schemes based on a watermarks mechanism
  tools/selftests/damon: update for regions prioritization of schemes
  mm/damon/dbgfs: support prioritization weights
  mm/damon/vaddr,paddr: support pageout prioritization
  mm/damon/schemes: prioritize regions within the quotas
  mm/damon/selftests: support schemes quotas
  mm/damon/dbgfs: support quotas of schemes
  ...
2021-11-06 14:08:17 -07:00
Feng Tang 8ca1b5a498 mm/page_alloc: detect allocation forbidden by cpuset and bail out early
There was a report that starting an Ubuntu in docker while using cpuset
to bind it to movable nodes (a node only has movable zone, like a node
for hotplug or a Persistent Memory node in normal usage) will fail due
to memory allocation failure, and then OOM is involved and many other
innocent processes got killed.

It can be reproduced with command:

    $ docker run -it --rm --cpuset-mems 4 ubuntu:latest bash -c "grep Mems_allowed /proc/self/status"

(where node 4 is a movable node)

  runc:[2:INIT] invoked oom-killer: gfp_mask=0x500cc2(GFP_HIGHUSER|__GFP_ACCOUNT), order=0, oom_score_adj=0
  CPU: 8 PID: 8291 Comm: runc:[2:INIT] Tainted: G        W I E     5.8.2-0.g71b519a-default #1 openSUSE Tumbleweed (unreleased)
  Hardware name: Dell Inc. PowerEdge R640/0PHYDR, BIOS 2.6.4 04/09/2020
  Call Trace:
   dump_stack+0x6b/0x88
   dump_header+0x4a/0x1e2
   oom_kill_process.cold+0xb/0x10
   out_of_memory.part.0+0xaf/0x230
   out_of_memory+0x3d/0x80
   __alloc_pages_slowpath.constprop.0+0x954/0xa20
   __alloc_pages_nodemask+0x2d3/0x300
   pipe_write+0x322/0x590
   new_sync_write+0x196/0x1b0
   vfs_write+0x1c3/0x1f0
   ksys_write+0xa7/0xe0
   do_syscall_64+0x52/0xd0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Mem-Info:
  active_anon:392832 inactive_anon:182 isolated_anon:0
   active_file:68130 inactive_file:151527 isolated_file:0
   unevictable:2701 dirty:0 writeback:7
   slab_reclaimable:51418 slab_unreclaimable:116300
   mapped:45825 shmem:735 pagetables:2540 bounce:0
   free:159849484 free_pcp:73 free_cma:0
  Node 4 active_anon:1448kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:0kB shmem:0kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB all_unreclaimable? no
  Node 4 Movable free:130021408kB min:9140kB low:139160kB high:269180kB reserved_highatomic:0KB active_anon:1448kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:130023424kB managed:130023424kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:292kB local_pcp:84kB free_cma:0kB
  lowmem_reserve[]: 0 0 0 0 0
  Node 4 Movable: 1*4kB (M) 0*8kB 0*16kB 1*32kB (M) 0*64kB 0*128kB 1*256kB (M) 1*512kB (M) 1*1024kB (M) 0*2048kB 31743*4096kB (M) = 130021156kB

  oom-kill:constraint=CONSTRAINT_CPUSET,nodemask=(null),cpuset=docker-9976a269caec812c134fa317f27487ee36e1129beba7278a463dd53e5fb9997b.scope,mems_allowed=4,global_oom,task_memcg=/system.slice/containerd.service,task=containerd,pid=4100,uid=0
  Out of memory: Killed process 4100 (containerd) total-vm:4077036kB, anon-rss:51184kB, file-rss:26016kB, shmem-rss:0kB, UID:0 pgtables:676kB oom_score_adj:0
  oom_reaper: reaped process 8248 (docker), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
  oom_reaper: reaped process 2054 (node_exporter), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
  oom_reaper: reaped process 1452 (systemd-journal), now anon-rss:0kB, file-rss:8564kB, shmem-rss:4kB
  oom_reaper: reaped process 2146 (munin-node), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
  oom_reaper: reaped process 8291 (runc:[2:INIT]), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB

The reason is that in this case, the target cpuset nodes only have
movable zone, while the creation of an OS in docker sometimes needs to
allocate memory in non-movable zones (dma/dma32/normal) like
GFP_HIGHUSER, and the cpuset limit forbids the allocation, then
out-of-memory killing is involved even when normal nodes and movable
nodes both have many free memory.

The OOM killer cannot help to resolve the situation as there is no
usable memory for the request in the cpuset scope.  The only reasonable
measure to take is to fail the allocation right away and have the caller
to deal with it.

So add a check for cases like this in the slowpath of allocation, and
bail out early returning NULL for the allocation.

As page allocation is one of the hottest path in kernel, this check will
hurt all users with sane cpuset configuration, add a static branch check
and detect the abnormal config in cpuset memory binding setup so that
the extra check cost in page allocation is not paid by everyone.

[thanks to Micho Hocko and David Rientjes for suggesting not handling
 it inside OOM code, adding cpuset check, refining comments]

Link: https://lkml.kernel.org/r/1632481657-68112-1-git-send-email-feng.tang@intel.com
Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-06 13:30:38 -07:00
Linus Torvalds a85373fe44 Merge branch 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:

 - The misc controller now reports allocation rejections through
   misc.events instead of printking

 - cgroup_mutex usage is reduced to improve scalability of some
   operations

 - vhost helper threads are now assigned to the right cgroup on cgroup2

 - Bug fixes

* 'for-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: bpf: Move wrapper for __cgroup_bpf_*() to kernel/bpf/cgroup.c
  cgroup: Fix rootcg cpu.stat guest double counting
  cgroup: no need for cgroup_mutex for /proc/cgroups
  cgroup: remove cgroup_mutex from cgroupstats_build
  cgroup: reduce dependency on cgroup_mutex
  cgroup: cgroup-v1: do not exclude cgrp_dfl_root
  cgroup: Make rebind_subsystems() disable v2 controllers all at once
  docs/cgroup: add entry for misc.events
  misc_cgroup: remove error log to avoid log flood
  misc_cgroup: introduce misc.events to count failures
2021-11-02 15:37:27 -07:00
He Fengqing 588e5d8766 cgroup: bpf: Move wrapper for __cgroup_bpf_*() to kernel/bpf/cgroup.c
In commit 324bda9e6c5a("bpf: multi program support for cgroup+bpf")
cgroup_bpf_*() called from kernel/bpf/syscall.c, but now they are only
used in kernel/bpf/cgroup.c, so move these function to
kernel/bpf/cgroup.c, like cgroup_bpf_replace().

Signed-off-by: He Fengqing <hefengqing@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-11-01 06:49:00 -10:00
Dan Schatzberg 81c49d39ae cgroup: Fix rootcg cpu.stat guest double counting
In account_guest_time in kernel/sched/cputime.c guest time is
attributed to both CPUTIME_NICE and CPUTIME_USER in addition to
CPUTIME_GUEST_NICE and CPUTIME_GUEST respectively. Therefore, adding
both to calculate usage results in double counting any guest time at
the rootcg.

Fixes: 936f2a70f2 ("cgroup: add cpu.stat file to root cgroup")
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-11-01 06:47:08 -10:00
Shakeel Butt 822bc9bac9 cgroup: no need for cgroup_mutex for /proc/cgroups
On the real systems, the cgroups hierarchies are setup early and just
once by the node controller, so, other than number of cgroups, all
information in /proc/cgroups remain same for the system uptime. Let's
remove the cgroup_mutex usage on reading /proc/cgroups. There is a
chance of inconsistent number of cgroups for co-mounted cgroups while
printing the information from /proc/cgroups but that is not a big
issue. In addition /proc/cgroups is a v1 specific interface, so the
dependency on it should reduce over time.

The main motivation for removing the cgroup_mutex from /proc/cgroups is
to reduce the avenues of its contention. On our fleet, we have observed
buggy application hammering on /proc/cgroups and drastically slowing
down the node controller on the system which have many negative
consequences on other workloads running on the system.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-10-25 07:26:00 -10:00
Shakeel Butt bb75842141 cgroup: remove cgroup_mutex from cgroupstats_build
The function cgroupstats_build extracts cgroup from the kernfs_node's
priv pointer which is a RCU pointer. So, there is no need to grab
cgroup_mutex. Just get the reference on the cgroup before using and
remove the cgroup_mutex altogether.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-10-25 07:24:03 -10:00
Shakeel Butt be28816971 cgroup: reduce dependency on cgroup_mutex
Currently cgroup_get_from_path() and cgroup_get_from_id() grab
cgroup_mutex before traversing the default hierarchy to find the
kernfs_node corresponding to the path/id and then extract the linked
cgroup. Since cgroup_mutex is still held, it is guaranteed that the
cgroup will be alive and the reference can be taken on it.

However similar guarantee can be provided without depending on the
cgroup_mutex and potentially reducing avenues of cgroup_mutex contentions.
The kernfs_node's priv pointer is RCU protected pointer and with just
rcu read lock we can grab the reference on the cgroup without
cgroup_mutex. So, remove cgroup_mutex from them.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-10-25 07:23:31 -10:00
Quanyang Wang 04f8ef5643 cgroup: Fix memory leak caused by missing cgroup_bpf_offline
When enabling CONFIG_CGROUP_BPF, kmemleak can be observed by running
the command as below:

    $mount -t cgroup -o none,name=foo cgroup cgroup/
    $umount cgroup/

unreferenced object 0xc3585c40 (size 64):
  comm "mount", pid 425, jiffies 4294959825 (age 31.990s)
  hex dump (first 32 bytes):
    01 00 00 80 84 8c 28 c0 00 00 00 00 00 00 00 00  ......(.........
    00 00 00 00 00 00 00 00 6c 43 a0 c3 00 00 00 00  ........lC......
  backtrace:
    [<e95a2f9e>] cgroup_bpf_inherit+0x44/0x24c
    [<1f03679c>] cgroup_setup_root+0x174/0x37c
    [<ed4b0ac5>] cgroup1_get_tree+0x2c0/0x4a0
    [<f85b12fd>] vfs_get_tree+0x24/0x108
    [<f55aec5c>] path_mount+0x384/0x988
    [<e2d5e9cd>] do_mount+0x64/0x9c
    [<208c9cfe>] sys_mount+0xfc/0x1f4
    [<06dd06e0>] ret_fast_syscall+0x0/0x48
    [<a8308cb3>] 0xbeb4daa8

This is because that since the commit 2b0d3d3e4f ("percpu_ref: reduce
memory footprint of percpu_ref in fast path") root_cgrp->bpf.refcnt.data
is allocated by the function percpu_ref_init in cgroup_bpf_inherit which
is called by cgroup_setup_root when mounting, but not freed along with
root_cgrp when umounting. Adding cgroup_bpf_offline which calls
percpu_ref_kill to cgroup_kill_sb can free root_cgrp->bpf.refcnt.data in
umount path.

This patch also fixes the commit 4bfc0bb2c6 ("bpf: decouple the lifetime
of cgroup_bpf from cgroup itself"). A cgroup_bpf_offline is needed to do a
cleanup that frees the resources which are allocated by cgroup_bpf_inherit
in cgroup_setup_root.

And inside cgroup_bpf_offline, cgroup_get() is at the beginning and
cgroup_put is at the end of cgroup_bpf_release which is called by
cgroup_bpf_offline. So cgroup_bpf_offline can keep the balance of
cgroup's refcount.

Fixes: 2b0d3d3e4f ("percpu_ref: reduce memory footprint of percpu_ref in fast path")
Fixes: 4bfc0bb2c6 ("bpf: decouple the lifetime of cgroup_bpf from cgroup itself")
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20211018075623.26884-1-quanyang.wang@windriver.com
2021-10-22 17:23:54 -07:00
Linus Torvalds 459ea72c6c Merge branch 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "All documentation / comment updates"

* 'for-5.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroupv2, docs: fix misinformation in "device controller" section
  cgroup/cpuset: Change references of cpuset_mutex to cpuset_rwsem
  docs/cgroup: remove some duplicate words
2021-10-11 17:16:41 -07:00
Vishal Verma 0061270307 cgroup: cgroup-v1: do not exclude cgrp_dfl_root
Found an issue within cgroup_attach_task_all() fn which seem
to exclude cgrp_dfl_root (cgroupv2) while attaching tasks to
the given cgroup. This was noticed when the system was running
qemu/kvm with kernel vhost helper threads. It appears that the
vhost layer which uses cgroup_attach_task_all() fn to assign the
vhost kthread to the right qemu cgroup works fine with cgroupv1
based configuration but not in cgroupv2. With cgroupv2, the vhost
helper thread ends up just belonging to the root cgroup as is
shown below:

$ stat -fc %T /sys/fs/cgroup/
cgroup2fs
$ sudo pgrep qemu
1916421
$ ps -eL | grep 1916421
1916421 1916421 ?        00:00:01 qemu-system-x86
1916421 1916431 ?        00:00:00 call_rcu
1916421 1916435 ?        00:00:00 IO mon_iothread
1916421 1916436 ?        00:00:34 CPU 0/KVM
1916421 1916439 ?        00:00:00 SPICE Worker
1916421 1916440 ?        00:00:00 vnc_worker
1916433 1916433 ?        00:00:00 vhost-1916421
1916437 1916437 ?        00:00:00 kvm-pit/1916421
$ cat /proc/1916421/cgroup
0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator
$ cat /proc/1916439/cgroup
0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator
$ cat /proc/1916433/cgroup
0::/

From above, it can be seen that the vhost kthread (PID: 1916433)
doesn't seem to belong the qemu cgroup like other qemu PIDs.

After applying this patch:

$ pgrep qemu
1643
$ ps -eL | grep 1643
   1643    1643 ?        00:00:00 qemu-system-x86
   1643    1645 ?        00:00:00 call_rcu
   1643    1648 ?        00:00:00 IO mon_iothread
   1643    1649 ?        00:00:00 CPU 0/KVM
   1643    1652 ?        00:00:00 SPICE Worker
   1643    1653 ?        00:00:00 vnc_worker
   1647    1647 ?        00:00:00 vhost-1643
   1651    1651 ?        00:00:00 kvm-pit/1643
$ cat /proc/1647/cgroup
0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Vishal Verma <vverma@digitalocean.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-10-05 06:13:21 -10:00
Daniel Borkmann 78cc316e95 bpf, cgroup: Assign cgroup in cgroup_sk_alloc when called from interrupt
If cgroup_sk_alloc() is called from interrupt context, then just assign the
root cgroup to skcd->cgroup. Prior to commit 8520e224f5 ("bpf, cgroups:
Fix cgroup v2 fallback on v1/v2 mixed mode") we would just return, and later
on in sock_cgroup_ptr(), we were NULL-testing the cgroup in fast-path, and
iff indeed NULL returning the root cgroup (v ?: &cgrp_dfl_root.cgrp). Rather
than re-adding the NULL-test to the fast-path we can just assign it once from
cgroup_sk_alloc() given v1/v2 handling has been simplified. The migration from
NULL test with returning &cgrp_dfl_root.cgrp to assigning &cgrp_dfl_root.cgrp
directly does /not/ change behavior for callers of sock_cgroup_ptr().

syzkaller was able to trigger a splat in the legacy netrom code base, where
the RX handler in nr_rx_frame() calls nr_make_new() which calls sk_alloc()
and therefore cgroup_sk_alloc() with in_interrupt() condition. Thus the NULL
skcd->cgroup, where it trips over on cgroup_sk_free() side given it expects
a non-NULL object. There are a few other candidates aside from netrom which
have similar pattern where in their accept-like implementation, they just call
to sk_alloc() and thus cgroup_sk_alloc() instead of sk_clone_lock() with the
corresponding cgroup_sk_clone() which then inherits the cgroup from the parent
socket. None of them are related to core protocols where BPF cgroup programs
are running from. However, in future, they should follow to implement a similar
inheritance mechanism.

Additionally, with a !CONFIG_CGROUP_NET_PRIO and !CONFIG_CGROUP_NET_CLASSID
configuration, the same issue was exposed also prior to 8520e224f5 due to
commit e876ecc67d ("cgroup: memcg: net: do not associate sock with unrelated
cgroup") which added the early in_interrupt() return back then.

Fixes: 8520e224f5 ("bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode")
Fixes: e876ecc67d ("cgroup: memcg: net: do not associate sock with unrelated cgroup")
Reported-by: syzbot+df709157a4ecaf192b03@syzkaller.appspotmail.com
Reported-by: syzbot+533f389d4026d86a2a95@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: syzbot+df709157a4ecaf192b03@syzkaller.appspotmail.com
Tested-by: syzbot+533f389d4026d86a2a95@syzkaller.appspotmail.com
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20210927123921.21535-1-daniel@iogearbox.net
2021-09-28 09:29:19 +02:00