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[Qemu-devel] [PATCH 24/36] virtio-net: out-of-bounds buffer write on loa
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PATCH 24/36] virtio-net: out-of-bounds buffer write on load |
Date: |
Mon, 5 May 2014 22:30:22 +0200 |
From: "Michael S. Tsirkin" <address@hidden>
CVE-2013-4149 QEMU 1.3.0 out-of-bounds buffer write in
virtio_net_load()@hw/net/virtio-net.c
> } else if (n->mac_table.in_use) {
> uint8_t *buf = g_malloc0(n->mac_table.in_use);
We are allocating buffer of size n->mac_table.in_use
> qemu_get_buffer(f, buf, n->mac_table.in_use * ETH_ALEN);
and read to the n->mac_table.in_use size buffer n->mac_table.in_use *
ETH_ALEN bytes, corrupting memory.
If adversary controls state then memory written there is controlled
by adversary.
Reviewed-by: Michael Roth <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
hw/net/virtio-net.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 0a8cb40..940a7cf 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1362,10 +1362,17 @@ static int virtio_net_load(QEMUFile *f, void *opaque,
int version_id)
if (n->mac_table.in_use <= MAC_TABLE_ENTRIES) {
qemu_get_buffer(f, n->mac_table.macs,
n->mac_table.in_use * ETH_ALEN);
- } else if (n->mac_table.in_use) {
- uint8_t *buf = g_malloc0(n->mac_table.in_use);
- qemu_get_buffer(f, buf, n->mac_table.in_use * ETH_ALEN);
- g_free(buf);
+ } else {
+ int64_t i;
+
+ /* Overflow detected - can happen if source has a larger MAC table.
+ * We simply set overflow flag so there's no need to maintain the
+ * table of addresses, discard them all.
+ * Note: 64 bit math to avoid integer overflow.
+ */
+ for (i = 0; i < (int64_t)n->mac_table.in_use * ETH_ALEN; ++i) {
+ qemu_get_byte(f);
+ }
n->mac_table.multi_overflow = n->mac_table.uni_overflow = 1;
n->mac_table.in_use = 0;
}
--
1.9.0
- [Qemu-devel] [PATCH 13/36] virtio: validate num_sg when mapping, (continued)
- [Qemu-devel] [PATCH 13/36] virtio: validate num_sg when mapping, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 16/36] tsc210x: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 15/36] ssd0323: fix buffer overun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 18/36] virtio-scsi: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 17/36] zaurus: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 21/36] savevm: Ignore minimum_version_id_old if there is no load_state_old, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 22/36] ssi-sd: fix buffer overrun on invalid state load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 19/36] vmstate: s/VMSTATE_INT32_LE/VMSTATE_INT32_POSITIVE_LE/, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 23/36] openpic: avoid buffer overrun on incoming migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 20/36] usb: sanity check setup_index+setup_len in post_load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 24/36] virtio-net: out-of-bounds buffer write on load,
Juan Quintela <=
- [Qemu-devel] [PATCH 27/36] Make qemu_peek_buffer loop until it gets it's data, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 26/36] Disallow outward migration while awaiting incoming migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 25/36] virtio: validate config_len on load, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 30/36] Init the XBZRLE.lock in ram_mig_init, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 28/36] Count used RAMBlock pages for migration_dirty_pages, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 29/36] Provide init function for ram migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 31/36] Coverity: Fix failure path for qemu_accept in migration, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 32/36] migration: remove duplicate code, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 33/36] XBZRLE: Fix one XBZRLE corruption issues, Juan Quintela, 2014/05/05
- [Qemu-devel] [PATCH 34/36] migration: Add counts of updating the dirty bitmap, Juan Quintela, 2014/05/05