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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 16:05:59 +0200
commit174c34d9cda1b5818419b8f5a332ced10755e52f (patch)
tree475ce82b16ea54aebc6adc5dd4e6cd7ef7caf32e
parentb33aa0dbd72f3af59bd633ccefc4fbcac85faec3 (diff)
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 03a369ccd28c..472714716be6 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -32,6 +32,9 @@ static void seq_set_overflow(struct seq_file *m)
static void *seq_buf_alloc(unsigned long size)
{
+ if (unlikely(size > MAX_RW_COUNT))
+ return NULL;
+
return kvmalloc(size, GFP_KERNEL_ACCOUNT);
}