4.14-stable review patch. If anyone has any objections, please let me know.
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From: Jason Wang jasowang@redhat.com
[ Upstream commit 850e088d5bbb333342fd4def08d0a4035f2b7126 ]
If we successfully linearize the packet, num_buf will be set to zero which may confuse error handling path which assumes num_buf is at least 1 and this can lead the code tries to pop the descriptor of next buffer. Fixing this by checking num_buf against 1 before decreasing.
Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set") Signed-off-by: Jason Wang jasowang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/virtio_net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -777,7 +777,7 @@ err_xdp: rcu_read_unlock(); err_skb: put_page(page); - while (--num_buf) { + while (num_buf-- > 1) { buf = virtqueue_get_buf(rq->vq, &len); if (unlikely(!buf)) { pr_debug("%s: rx error: %d buffers missing\n",