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| author | Sasha Levin <levinsasha928@gmail.com> | 2012-01-12 17:17:40 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-12 20:13:04 -0800 |
| commit | 2ccd4f4d4737b37e21dd92c8c584c23cd87740a2 (patch) | |
| tree | 7c4048fc709612fa057e39350352445f2f26d211 | |
| parent | 888a214dc4c65e1486ef7d3ac6b0cf93ae3cc2c7 (diff) | |
| download | linux-2ccd4f4d4737b37e21dd92c8c584c23cd87740a2.tar.gz linux-2ccd4f4d4737b37e21dd92c8c584c23cd87740a2.tar.xz | |
pipe: fail cleanly when root tries F_SETPIPE_SZ with big size
When a user with the CAP_SYS_RESOURCE cap tries to F_SETPIPE_SZ a pipe
with size bigger than kmalloc() can alloc it spits out an ugly warning:
------------[ cut here ]------------
WARNING: at mm/page_alloc.c:2095 __alloc_pages_nodemask+0x5d3/0x7a0()
Pid: 733, comm: a.out Not tainted 3.2.0-rc1+ #4
Call Trace:
warn_slowpath_common+0x75/0xb0
warn_slowpath_null+0x15/0x20
__alloc_pages_nodemask+0x5d3/0x7a0
__get_free_pages+0x12/0x50
__kmalloc+0x12b/0x150
pipe_set_size+0x75/0x120
pipe_fcntl+0xf8/0x140
do_fcntl+0x2d4/0x410
sys_fcntl+0x66/0xa0
system_call_fastpath+0x16/0x1b
---[ end trace 432f702e6db7b5ee ]---
Instead, make kcalloc() handle the overflow case and fail quietly.
[akpm@linux-foundation.org: switch to sizeof(*bufs) for 80-column niceness]
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/pipe.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/pipe.c b/fs/pipe.c index f0e485d54e64..a932ced92a16 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1137,7 +1137,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages) if (nr_pages < pipe->nrbufs) return -EBUSY; - bufs = kcalloc(nr_pages, sizeof(struct pipe_buffer), GFP_KERNEL); + bufs = kcalloc(nr_pages, sizeof(*bufs), GFP_KERNEL | __GFP_NOWARN); if (unlikely(!bufs)) return -ENOMEM; |