From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36674) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF81F-0005It-2W for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:41:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XF811-0003x2-HY for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:41:08 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:40780) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XF811-0003wt-Ad for qemu-devel@nongnu.org; Wed, 06 Aug 2014 16:40:55 -0400 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 6 Aug 2014 14:40:54 -0600 From: Michael Roth Date: Wed, 6 Aug 2014 15:38:16 -0500 Message-Id: <1407357598-21541-7-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1407357598-21541-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1407357598-21541-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 006/108] virtio-net: fix buffer overflow on invalid state load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org From: "Michael S. Tsirkin" CVE-2013-4148 QEMU 1.0 integer conversion in virtio_net_load()@hw/net/virtio-net.c Deals with loading a corrupted savevm image. > n->mac_table.in_use = qemu_get_be32(f); in_use is int so it can get negative when assigned 32bit unsigned value. > /* MAC_TABLE_ENTRIES may be different from the saved image */ > if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) { passing this check ^^^ > qemu_get_buffer(f, n->mac_table.macs, > n->mac_table.in_use * ETH_ALEN); with good in_use value, "n->mac_table.in_use * ETH_ALEN" can get positive and bigger than mac_table.macs. For example 0x81000000 satisfies this condition when ETH_ALEN is 6. Fix it by making the value unsigned. For consistency, change first_multi as well. Note: all call sites were audited to confirm that making them unsigned didn't cause any issues: it turns out we actually never do math on them, so it's easy to validate because both values are always <= MAC_TABLE_ENTRIES. Reviewed-by: Michael Roth Signed-off-by: Michael S. Tsirkin Reviewed-by: Laszlo Ersek Signed-off-by: Juan Quintela (cherry picked from commit 71f7fe48e10a8437c9d42d859389f37157f59980) Signed-off-by: Michael Roth --- include/hw/virtio/virtio-net.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h index df60f16..4b32440 100644 --- a/include/hw/virtio/virtio-net.h +++ b/include/hw/virtio/virtio-net.h @@ -176,8 +176,8 @@ typedef struct VirtIONet { uint8_t nobcast; uint8_t vhost_started; struct { - int in_use; - int first_multi; + uint32_t in_use; + uint32_t first_multi; uint8_t multi_overflow; uint8_t uni_overflow; uint8_t *macs; -- 1.9.1