From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47021) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a3J3H-00064d-Tg for qemu-devel@nongnu.org; Mon, 30 Nov 2015 02:39:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a3J3H-00020A-0O for qemu-devel@nongnu.org; Mon, 30 Nov 2015 02:39:11 -0500 From: Jason Wang Date: Mon, 30 Nov 2015 15:38:23 +0800 Message-Id: <1448869103-16281-2-git-send-email-jasowang@redhat.com> In-Reply-To: <1448869103-16281-1-git-send-email-jasowang@redhat.com> References: <1448869103-16281-1-git-send-email-jasowang@redhat.com> Subject: [Qemu-devel] [PATCH for 2.5 2/2] pcnet: fix rx buffer overflow(CVE-2015-7512) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: jasowang@redhat.com, qemu-devel@nongnu.org Cc: Prasad J Pandit , qemu-stable@nongnu.org Backends could provide a packet whose length is greater than buffer size. Check for this and truncate the packet to avoid rx buffer overflow in this case. Cc: Prasad J Pandit Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang --- hw/net/pcnet.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c index 309c40b..1f4a3db 100644 --- a/hw/net/pcnet.c +++ b/hw/net/pcnet.c @@ -1064,6 +1064,12 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_) int pktcount = 0; if (!s->looptest) { + if (size > 4092) { +#ifdef PCNET_DEBUG_RMD + fprintf(stderr, "pcnet: truncates rx packet.\n"); +#endif + size = 4092; + } memcpy(src, buf, size); /* no need to compute the CRC */ src[size] = 0; -- 2.5.0