From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46325) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYSfp-0005G4-F5 for qemu-devel@nongnu.org; Wed, 24 Feb 2016 01:11:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aYSfl-0000hD-Cy for qemu-devel@nongnu.org; Wed, 24 Feb 2016 01:11:45 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45962) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYSfl-0000h6-7S for qemu-devel@nongnu.org; Wed, 24 Feb 2016 01:11:41 -0500 From: P J P Date: Wed, 24 Feb 2016 11:41:33 +0530 Message-Id: <1456294293-26027-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH v2] net: ne2000: check ring buffer control registers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Yang Hongke , Jason Wang , Prasad J Pandit From: Prasad J Pandit Ne2000 NIC uses ring buffer of NE2000_MEM_SIZE(49152) bytes to process network packets. Registers PSTART & PSTOP define ring buffer size & location. Setting these registers to invalid values could lead to infinite loop or OOB r/w access issues. Add check to avoid it. Reported-by: Yang Hongke Signed-off-by: Prasad J Pandit --- hw/net/ne2000.c | 4 ++++ 1 file changed, 4 insertions(+) Update per review: -> https://lists.gnu.org/archive/html/qemu-devel/2016-02/msg05522.html diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c index b032212..ced4666 100644 --- a/hw/net/ne2000.c +++ b/hw/net/ne2000.c @@ -154,6 +154,10 @@ static int ne2000_buffer_full(NE2000State *s) { int avail, index, boundary; + if (s->stop <= s->start) { + return 1; + } + index = s->curpag << 8; boundary = s->boundary << 8; if (index < boundary) -- 2.5.0