On Mon, May 25, 2026 at 11:15:12AM +0000, malin (R) wrote:
From 9eea4f61a4dca97f56c23e12267219bf791a20d1 Mon Sep 17 00:00:00 2001 From: Jingguo Tan <[email protected]> Date: Fri, 22 May 2026 19:53:45 +0800 Subject: [PATCH net] vsock/virtio: bind uarg before filling zerocopy skbvirtio_transport_send_pkt_info() allocates or reuses the zerocopy uarg before entering the send loop, but virtio_transport_alloc_skb() still fills the skb before it inherits that uarg. When fixed-buffer vectored zerocopy hits MAX_SKB_FRAGS, io_sg_from_iter() may partially attach managed frags and return -EMSGSIZE. The rollback path calls kfree_skb() to free an skb that carries SKBFL_MANAGED_FRAG_REFS but no uarg, so skb_release_data() falls through to ordinary frag unref. Pass the uarg into virtio_transport_alloc_skb() and bind it immediately before virtio_transport_fill_skb(). This keeps control or no-payload skbs untouched while ensuring success and rollback share one lifetime rule. Fixes: 581512a6dc93 ("vsock/virtio: MSG_ZEROCOPY flag support") Signed-off-by: Lin Ma <[email protected]> Signed-off-by: Rongzhen Cui <[email protected]> Signed-off-by: Jingguo Tan <[email protected]> --- net/vmw_vsock/virtio_transport_common.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
Reviewed-by: Stefano Garzarella <[email protected]>

