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| author | Prakash Gupta <guptap@codeaurora.org> | 2017-08-18 15:16:21 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-08-18 15:32:02 -0700 |
| commit | da094e42848e3c36feaa3b5271e53983fd45424f (patch) | |
| tree | b33c69a6eb206dc58225c2e8a2920fafd3804ca1 /mm/cma_debug.c | |
| parent | eb61b5911bdc923875cde99eb25203a0e2b06d43 (diff) | |
| download | lwn-da094e42848e3c36feaa3b5271e53983fd45424f.tar.gz lwn-da094e42848e3c36feaa3b5271e53983fd45424f.zip | |
mm/cma_debug.c: fix stack corruption due to sprintf usage
name[] in cma_debugfs_add_one() can only accommodate 16 chars including
NULL to store sprintf output. It's common for cma device name to be
larger than 15 chars. This can cause stack corrpution. If the gcc
stack protector is turned on, this can cause a panic due to stack
corruption.
Below is one example trace:
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:
ffffff8e69a75730
Call trace:
dump_backtrace+0x0/0x2c4
show_stack+0x20/0x28
dump_stack+0xb8/0xf4
panic+0x154/0x2b0
print_tainted+0x0/0xc0
cma_debugfs_init+0x274/0x290
do_one_initcall+0x5c/0x168
kernel_init_freeable+0x1c8/0x280
Fix the short sprintf buffer in cma_debugfs_add_one() by using
scnprintf() instead of sprintf().
Link: http://lkml.kernel.org/r/1502446217-21840-1-git-send-email-guptap@codeaurora.org
Fixes: f318dd083c81 ("cma: Store a name in the cma structure")
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/cma_debug.c')
| -rw-r--r-- | mm/cma_debug.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/cma_debug.c b/mm/cma_debug.c index 595b757bef72..c03ccbc405a0 100644 --- a/mm/cma_debug.c +++ b/mm/cma_debug.c @@ -167,7 +167,7 @@ static void cma_debugfs_add_one(struct cma *cma, int idx) char name[16]; int u32s; - sprintf(name, "cma-%s", cma->name); + scnprintf(name, sizeof(name), "cma-%s", cma->name); tmp = debugfs_create_dir(name, cma_debugfs_root); |