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| author | Vasily Averin <vvs@virtuozzo.com> | 2021-06-30 18:57:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-01 11:06:07 -0700 |
| commit | fc37a3b8b4388e73e8e3525556d9f1feeb232bb9 (patch) | |
| tree | 4a1adfb461437e5dff7626b725c7f77ab11dbcae /drivers/dio | |
| parent | 3b52348345b2cfe038d317de52bcdef788c6520d (diff) | |
| download | linux-fc37a3b8b4388e73e8e3525556d9f1feeb232bb9.tar.bz2 | |
ipc sem: use kvmalloc for sem_undo allocation
Patch series "ipc: allocations cleanup", v2.
Some ipc objects use the wrong allocation functions: small objects can use
kmalloc(), and vice versa, potentially large objects can use kmalloc().
This patch (of 2):
Size of sem_undo can exceed one page and with the maximum possible nsems =
32000 it can grow up to 64Kb. Let's switch its allocation to kvmalloc to
avoid user-triggered disruptive actions like OOM killer in case of
high-order memory shortage.
User triggerable high order allocations are quite a problem on heavily
fragmented systems. They can be a DoS vector.
Link: https://lkml.kernel.org/r/ebc3ac79-3190-520d-81ce-22ad194986ec@virtuozzo.com
Link: https://lkml.kernel.org/r/a6354fd9-2d55-2e63-dd4d-fa7dc1d11134@virtuozzo.com
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/dio')
0 files changed, 0 insertions, 0 deletions