From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33289) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adCRv-0004VB-SG for qemu-devel@nongnu.org; Tue, 08 Mar 2016 02:53:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1adCRu-00009F-UE for qemu-devel@nongnu.org; Tue, 08 Mar 2016 02:52:59 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47938) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1adCRu-000099-H9 for qemu-devel@nongnu.org; Tue, 08 Mar 2016 02:52:58 -0500 From: Jason Wang Date: Tue, 8 Mar 2016 15:52:33 +0800 Message-Id: <1457423564-9724-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1457423564-9724-1-git-send-email-jasowang@redhat.com> References: <1457423564-9724-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PULL V2 01/12] net: ne2000: check ring buffer control registers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: peter.maydell@linaro.org, qemu-devel@nongnu.org Cc: 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 Tested-by: Yang Hongke Signed-off-by: Prasad J Pandit Signed-off-by: Jason Wang --- hw/net/ne2000.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/net/ne2000.c b/hw/net/ne2000.c index e408083..f0feaf9 100644 --- a/hw/net/ne2000.c +++ b/hw/net/ne2000.c @@ -155,6 +155,10 @@ 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