On Thu, 11 Dec 2025 14:57:08 +0800 Edward Adam Davis wrote:

In zerocopy_fill_skb_from_iter(), if two copy operations are performed
and the first one succeeds while the second one fails, it returns a
failure but the count in iterator has already been decremented due to
the first successful copy. This ultimately affects the local variable
rest_len in virtio_transport_send_pkt_info(), causing the remaining
count in rest_len to be greater than the actual iterator count. As a
result, packet sending operations continue even when the iterator count
is zero, which further leads to skb->len being 0 and triggers the warning
reported by syzbot [1].

Please address the feedback from previous revision and when you repost
use net as the subject tag.
-- 
pw-bot: cr