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| author | Jason Wang <jasowang@redhat.com> | 2024-01-02 11:29:01 +0800 |
|---|---|---|
| committer | Jason Wang <jasowang@redhat.com> | 2024-01-25 14:58:00 +0800 |
| commit | 2220e8189fb94068dbad333228659fbac819abb0 (patch) | |
| tree | 6bba50644b12a34b2d0e406f07db9450d15157e8 | |
| parent | 4a4efae44f19528589204581e9e2fab69c5d39aa (diff) | |
| download | qemu-2220e8189fb94068dbad333228659fbac819abb0.zip qemu-2220e8189fb94068dbad333228659fbac819abb0.tar.gz qemu-2220e8189fb94068dbad333228659fbac819abb0.tar.bz2 | |
virtio-net: correctly copy vnet header when flushing TX
When HASH_REPORT is negotiated, the guest_hdr_len might be larger than
the size of the mergeable rx buffer header. Using
virtio_net_hdr_mrg_rxbuf during the header swap might lead a stack
overflow in this case. Fixing this by using virtio_net_hdr_v1_hash
instead.
Reported-by: Xiao Lei <leixiao.nop@zju.edu.cn>
Cc: Yuri Benditovich <yuri.benditovich@daynix.com>
Cc: qemu-stable@nongnu.org
Cc: Mauro Matteo Cascella <mcascell@redhat.com>
Fixes: CVE-2023-6693
Fixes: e22f0603fb2f ("virtio-net: reference implementation of hash report")
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
| -rw-r--r-- | hw/net/virtio-net.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 7a2846f..5a79bc3 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -674,6 +674,11 @@ static void virtio_net_set_mrg_rx_bufs(VirtIONet *n, int mergeable_rx_bufs, n->mergeable_rx_bufs = mergeable_rx_bufs; + /* + * Note: when extending the vnet header, please make sure to + * change the vnet header copying logic in virtio_net_flush_tx() + * as well. + */ if (version_1) { n->guest_hdr_len = hash_report ? sizeof(struct virtio_net_hdr_v1_hash) : @@ -2693,7 +2698,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) ssize_t ret; unsigned int out_num; struct iovec sg[VIRTQUEUE_MAX_SIZE], sg2[VIRTQUEUE_MAX_SIZE + 1], *out_sg; - struct virtio_net_hdr_mrg_rxbuf mhdr; + struct virtio_net_hdr_v1_hash vhdr; elem = virtqueue_pop(q->tx_vq, sizeof(VirtQueueElement)); if (!elem) { @@ -2710,7 +2715,7 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) } if (n->has_vnet_hdr) { - if (iov_to_buf(out_sg, out_num, 0, &mhdr, n->guest_hdr_len) < + if (iov_to_buf(out_sg, out_num, 0, &vhdr, n->guest_hdr_len) < n->guest_hdr_len) { virtio_error(vdev, "virtio-net header incorrect"); virtqueue_detach_element(q->tx_vq, elem, 0); @@ -2718,8 +2723,8 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) return -EINVAL; } if (n->needs_vnet_hdr_swap) { - virtio_net_hdr_swap(vdev, (void *) &mhdr); - sg2[0].iov_base = &mhdr; + virtio_net_hdr_swap(vdev, (void *) &vhdr); + sg2[0].iov_base = &vhdr; sg2[0].iov_len = n->guest_hdr_len; out_num = iov_copy(&sg2[1], ARRAY_SIZE(sg2) - 1, out_sg, out_num, |