| From 8cae8cd89f05f6de223d63e6d15e31c8ba9cf53b Mon Sep 17 00:00:00 2001 |
| From: Eric Sandeen <sandeen@redhat.com> |
| Date: Tue, 13 Jul 2021 17:49:23 +0200 |
| Subject: [PATCH] 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: 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> |
| --- |
| fs/seq_file.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| diff --git a/fs/seq_file.c b/fs/seq_file.c |
| index b117b212ef2887..4a2cda04d3e293 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); |
| } |
| |
