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authorSasha Levin <levinsasha928@gmail.com>2012-01-12 17:17:40 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-12 20:13:04 -0800
commit2ccd4f4d4737b37e21dd92c8c584c23cd87740a2 (patch)
tree7c4048fc709612fa057e39350352445f2f26d211
parent888a214dc4c65e1486ef7d3ac6b0cf93ae3cc2c7 (diff)
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.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/pipe.c b/fs/pipe.c
index f0e485d54e6..a932ced92a1 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;