From: Eric Sandeen <sandeen@redhat.com> stable inclusion from stable-5.10.52 commit 174c34d9cda1b5818419b8f5a332ced10755e52f bugzilla: 331 CVE: CVE-2021-33909 --------------------------------------------------------------- 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> --- fs/seq_file.c | 3 +++ 1 file changed, 3 insertions(+) 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); } -- 2.20.1