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authorStefan Hajnoczi <stefanha@redhat.com>2016-08-04 16:52:53 +0300
committerMichael S. Tsirkin <mst@redhat.com>2016-08-09 13:42:37 +0300
commit3fda5d6e580193fa005014355b3a61498f1b3ae0 (patch)
tree351ecd0bebf5e2e863ad233fe356cf54a08d9ce3 /drivers/vhost
parent1b8553c04bf95180eb91be94f089a1e8b38cfd62 (diff)
downloadlinux-3fda5d6e580193fa005014355b3a61498f1b3ae0.tar.xz
vhost/vsock: fix vhost virtio_vsock_pkt use-after-free
Stash the packet length in a local variable before handing over ownership of the packet to virtio_transport_recv_pkt() or virtio_transport_free_pkt(). This patch solves the use-after-free since pkt is no longer guaranteed to be alive. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
-rw-r--r--drivers/vhost/vsock.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 0ddf3a2dbfc4..e3b30ea9ece5 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -307,6 +307,8 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
vhost_disable_notify(&vsock->dev, vq);
for (;;) {
+ u32 len;
+
if (!vhost_vsock_more_replies(vsock)) {
/* Stop tx until the device processes already
* pending replies. Leave tx virtqueue
@@ -334,13 +336,15 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
continue;
}
+ len = pkt->len;
+
/* Only accept correctly addressed packets */
if (le64_to_cpu(pkt->hdr.src_cid) == vsock->guest_cid)
virtio_transport_recv_pkt(pkt);
else
virtio_transport_free_pkt(pkt);
- vhost_add_used(vq, head, sizeof(pkt->hdr) + pkt->len);
+ vhost_add_used(vq, head, sizeof(pkt->hdr) + len);
added = true;
}