From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51425) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aW0uL-0007MT-8m for qemu-devel@nongnu.org; Wed, 17 Feb 2016 07:08:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aW0uH-00069c-6c for qemu-devel@nongnu.org; Wed, 17 Feb 2016 07:08:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:42885) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aW0uH-00069W-14 for qemu-devel@nongnu.org; Wed, 17 Feb 2016 07:08:33 -0500 From: P J P Date: Wed, 17 Feb 2016 17:38:24 +0530 Message-Id: <1455710904-13368-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH] net: check packet payload length List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Jason Wang , Prasad J Pandit , Liu Ling From: Prasad J Pandit While computing IP checksum, 'net_checksum_calculate' reads payload length from the packet. It could exceed the given 'data' buffer size. Add a check to avoid it. Reported-by: Liu Ling Signed-off-by: Prasad J Pandit --- net/checksum.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/checksum.c b/net/checksum.c index 14c0855..e51698c 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -76,8 +76,9 @@ void net_checksum_calculate(uint8_t *data, int length) return; } - if (plen < csum_offset+2) - return; + if ((plen < csum_offset + 2) || (plen + hlen >= length)) { + return; + } data[14+hlen+csum_offset] = 0; data[14+hlen+csum_offset+1] = 0; -- 2.5.0