Commit 82280f83 authored Jul 13, 2021 by Eric Sandeen Committed by Todd Kjos Dec 06, 2021

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: 058504ed ("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>

parent 6c0d8030

fs/seq_file.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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