FROMGIT: vsock/virtio: Validate length in packet header before skb_put()

When receiving a vsock packet in the guest, only the virtqueue buffer
size is validated prior to virtio_vsock_skb_rx_put(). Unfortunately,
virtio_vsock_skb_rx_put() uses the length from the packet header as the
length argument to skb_put(), potentially resulting in SKB overflow if
the host has gone wonky.

Validate the length as advertised by the packet header before calling
virtio_vsock_skb_rx_put().

Cc: <stable@vger.kernel.org>
Fixes: 71dc9ec9ac ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: Will Deacon <will@kernel.org>
Message-Id: <20250717090116.11987-3-will@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
(cherry picked from commit 774a14c4d15d0515f0ff88dfab7e08e22b07eb3e
 git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git vhost)
Bug: 421244320
Signed-off-by: Will Deacon <willdeacon@google.com>
Change-Id: I2d6a8ce7d6284a262e24e5bec4a35796f018e64f
This commit is contained in:
Will Deacon
2025-07-17 10:01:09 +01:00
committed by Isaac Manjarres
parent b8845cd48c
commit 20063c7e48

View File

@@ -539,8 +539,9 @@ static void virtio_transport_rx_work(struct work_struct *work)
do {
virtqueue_disable_cb(vq);
for (;;) {
unsigned int len, payload_len;
struct virtio_vsock_hdr *hdr;
struct sk_buff *skb;
unsigned int len;
if (!virtio_transport_more_replies(vsock)) {
/* Stop rx until the device processes already
@@ -557,12 +558,19 @@ static void virtio_transport_rx_work(struct work_struct *work)
vsock->rx_buf_nr--;
/* Drop short/long packets */
if (unlikely(len < sizeof(struct virtio_vsock_hdr) ||
if (unlikely(len < sizeof(*hdr) ||
len > virtio_vsock_skb_len(skb))) {
kfree_skb(skb);
continue;
}
hdr = virtio_vsock_hdr(skb);
payload_len = le32_to_cpu(hdr->len);
if (unlikely(payload_len > len - sizeof(*hdr))) {
kfree_skb(skb);
continue;
}
virtio_vsock_skb_rx_put(skb);
virtio_transport_deliver_tap_pkt(skb);
virtio_transport_recv_pkt(&virtio_transport, skb);