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authorEric Sandeen <sandeen@redhat.com>2021-07-13 17:49:23 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-07-20 16:21:16 +0200
commitc5157b3e775dac31d51b11f993a06a84dc11fc8c (patch)
tree51e7336714bb4bd7a55028af16759974867fedda
parent8be8d4ba1c4d4f5fb316957965f9f8d5f110f5b5 (diff)
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seq_file: disallow extremely large seq buffer allocations
commit 8cae8cd89f05f6de223d63e6d15e31c8ba9cf53b upstream. There is no reasonable need for a buffer larger than this, and it avoids int overflow pitfalls. Fixes: 058504edd026 ("fs/seq_file: fallback to vmalloc allocation") Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Reported-by: Qualys Security Advisory <qsa@qualys.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/seq_file.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c
index 368bfb92b115..3ade39e02bb7 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -28,6 +28,9 @@ static void *seq_buf_alloc(unsigned long size)
void *buf;
gfp_t gfp = GFP_KERNEL;
+ if (unlikely(size > MAX_RW_COUNT))
+ return NULL;
+
/*
* For high order allocations, use __GFP_NORETRY to avoid oom-killing -
* it's better to fall back to vmalloc() than to kill things. For small