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| author |   Tejun Heo <tj@kernel.org> | 2018-03-14 12:10:17 -0700 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2018-03-14 12:10:17 -0700 |
| commit | a6d7cff472eea87d96899a20fa718d2bab7109f3 (patch) | |
| tree | eb61b607a6fb3b77781c3e526ca33e0f885eb8b1 /drivers | |
| parent | Merge tag 'usb-4.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb (diff) | |
| download | linux-dev-a6d7cff472eea87d96899a20fa718d2bab7109f3.tar.xz linux-dev-a6d7cff472eea87d96899a20fa718d2bab7109f3.zip | |
fs/aio: Add explicit RCU grace period when freeing kioctx
While fixing refcounting, e34ecee2ae79 ("aio: Fix a trinity splat")
incorrectly removed explicit RCU grace period before freeing kioctx.
The intention seems to be depending on the internal RCU grace periods
of percpu_ref; however, percpu_ref uses a different flavor of RCU,
sched-RCU. This can lead to kioctx being freed while RCU read
protected dereferences are still in progress.
Fix it by updating free_ioctx() to go through call_rcu() explicitly.
v2: Comment added to explain double bouncing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Fixes: e34ecee2ae79 ("aio: Fix a trinity splat")
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org # v3.13+
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions