Дмитрий Фролов <fro...@swemel.ru> writes: > ping > > https://patchew.org/QEMU/20240527133140.218300-2-fro...@swemel.ru/ > > On 27.05.2024 16:31, Dmitry Frolov wrote: >> A crash found while fuzzing device virtio-net-socket-check-used. >> Assertion "offset == 0" in iov_copy() fails if less than guest_hdr_len bytes >> were transmited. >> >> Signed-off-by: Dmitry Frolov <fro...@swemel.ru> >> --- >> hw/net/virtio-net.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c >> index 24e5e7d347..603b80a50a 100644 >> --- a/hw/net/virtio-net.c >> +++ b/hw/net/virtio-net.c >> @@ -2783,6 +2783,12 @@ static int32_t virtio_net_flush_tx(VirtIONetQueue *q) >> */ >> assert(n->host_hdr_len <= n->guest_hdr_len); >> if (n->host_hdr_len != n->guest_hdr_len) { >> + if (iov_size(out_sg, out_num) < n->guest_hdr_len) { >> + virtio_error(vdev, "virtio-net header is invalid"); >> + virtqueue_detach_element(q->tx_vq, elem, 0); >> + g_free(elem); >> + return -EINVAL; >> + }
Isn't this basically another case for goto detach? Although the use of goto's here is a bit of a code smell. I wonder if there is any way to better structure this function and take care of the auto-freeing of elements? >> unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg), >> out_sg, out_num, >> 0, n->host_hdr_len); -- Alex Bennée Virtualisation Tech Lead @ Linaro
