Re: [PATCH net 1/2] vhost_net: fix ubuf refcount incorrectly when sendmsg fails
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2020-12-15 02:47:46
Also in:
virtualization
On Mon, Dec 14, 2020 at 8:59 PM wangyunjian [off-list ref] wrote:
From: Yunjian Wang <redacted>
Currently the vhost_zerocopy_callback() maybe be called to decrease
the refcount when sendmsg fails in tun. The error handling in vhost
handle_tx_zerocopy() will try to decrease the same refcount again.
This is wrong. To fix this issue, we only call vhost_net_ubuf_put()
when vq->heads[nvq->desc].len == VHOST_DMA_IN_PROGRESS.
Fixes: 4477138fa0ae ("tun: properly test for IFF_UP")
Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Yunjian Wang <redacted>
Patch looks good to me. Thanks.
But I think the right Fixes tag would be
Fixes: 0690899b4d45 ("tun: experimental zero copy tx support")