seq_file: disallow extremely large seq buffer allocations

There is no reasonable need for a buffer larger than this, and it avoids
int overflow pitfalls.

Fixes: 058504edd0 ("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>
This commit is contained in:
Eric Sandeen 2021-07-13 17:49:23 +02:00 committed by Linus Torvalds
parent 2734d6c1b1
commit 8cae8cd89f
1 changed files with 3 additions and 0 deletions

View File

@ -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);
}