From 798f06c3737233a836584a72565f8076907365d9 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Wed, 14 May 2014 08:31:36 +0200 Subject: [PATCH 09/31] virtio-net: fix buffer overflow on invalid state load RH-Author: Michael S. Tsirkin Message-id: <1400056285-6688-1-git-send-email-mst@redhat.com> Patchwork-id: 58855 O-Subject: [PATCH qemu-kvm RHEL7.1] virtio-net: fix buffer overflow on invalid state load Bugzilla: 1095678 RH-Acked-by: Dr. David Alan Gilbert (git) RH-Acked-by: Xiao Wang RH-Acked-by: Amos Kong 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) Bugzilla: 1095678 Tested: on developer's box Brew build: http://brewweb.devel.redhat.com/brew/taskinfo?taskID=7452039 --- include/hw/virtio/virtio-net.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) Signed-off-by: Miroslav Rezanina --- include/hw/virtio/virtio-net.h | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h index 75723a8..a02fc50 100644 --- a/include/hw/virtio/virtio-net.h +++ b/include/hw/virtio/virtio-net.h @@ -174,8 +174,8 @@ 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; -- 1.7.1