From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36072) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aoPWV-0004Y7-Rc for qemu-devel@nongnu.org; Fri, 08 Apr 2016 02:04:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aoPWR-0001K4-S7 for qemu-devel@nongnu.org; Fri, 08 Apr 2016 02:04:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50694) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aoPWR-0001Jy-MS for qemu-devel@nongnu.org; Fri, 08 Apr 2016 02:03:59 -0400 From: P J P Date: Fri, 8 Apr 2016 11:33:48 +0530 Message-Id: <1460095428-22698-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH v3] net: stellaris_enet: check packet length against receive buffer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Jason Wang , Oleksandr Bazhaniuk , Peter Maydell , Prasad J Pandit From: Prasad J Pandit When receiving packets over Stellaris ethernet controller, it uses receive buffer of size 2048 bytes. In case the controller accepts large(MTU) packets, it could lead to memory corruption. Add check to avoid it. Reported-by: Oleksandr Bazhaniuk Signed-off-by: Prasad J Pandit --- hw/net/stellaris_enet.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) Update per review: -> https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg01173.html diff --git a/hw/net/stellaris_enet.c b/hw/net/stellaris_enet.c index 21a4773..fc48ba8 100644 --- a/hw/net/stellaris_enet.c +++ b/hw/net/stellaris_enet.c @@ -235,8 +235,18 @@ static ssize_t stellaris_enet_receive(NetClientState *nc, const uint8_t *buf, si n = s->next_packet + s->np; if (n >= 31) n -= 31; + + if (size >= sizeof(s->rx[n].data) - 6) { + /* If the packet won't fit into the + * emulated 2K RAM, this is reported + * as a FIFO overrun error. + */ + s->ris |= SE_INT_FOV; + stellaris_enet_update(s); + return -1; + } + s->np++; - s->rx[n].len = size + 6; p = s->rx[n].data; *(p++) = (size + 6); -- 2.5.5