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Message-ID: <1609207308-20544-1-git-send-email-wangyunjian@huawei.com>
Date: Tue, 29 Dec 2020 10:01:48 +0800
From: wangyunjian <wangyunjian@...wei.com>
To: <netdev@...r.kernel.org>
CC: <davem@...emloft.net>, <kuba@...nel.org>, <mst@...hat.com>,
<jasowang@...hat.com>, <willemdebruijn.kernel@...il.com>,
<virtualization@...ts.linux-foundation.org>,
<jerry.lilijun@...wei.com>, <chenchanghu@...wei.com>,
<xudingke@...wei.com>, <brian.huangbin@...wei.com>,
Yunjian Wang <wangyunjian@...wei.com>
Subject: [PATCH net v6] vhost_net: fix ubuf refcount incorrectly when sendmsg fails
From: Yunjian Wang <wangyunjian@...wei.com>
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: bab632d69ee4 ("vhost: vhost TX zero-copy support")
Signed-off-by: Yunjian Wang <wangyunjian@...wei.com>
Acked-by: Willem de Bruijn <willemb@...gle.com>
Acked-by: Michael S. Tsirkin <mst@...hat.com>
Acked-by: Jason Wang <jasowang@...hat.com>
---
v6:
* update patch Fixes tag
---
drivers/vhost/net.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 531a00d703cd..c8784dfafdd7 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -863,6 +863,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
size_t len, total_len = 0;
int err;
struct vhost_net_ubuf_ref *ubufs;
+ struct ubuf_info *ubuf;
bool zcopy_used;
int sent_pkts = 0;
@@ -895,9 +896,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
/* use msg_control to pass vhost zerocopy ubuf info to skb */
if (zcopy_used) {
- struct ubuf_info *ubuf;
ubuf = nvq->ubuf_info + nvq->upend_idx;
-
vq->heads[nvq->upend_idx].id = cpu_to_vhost32(vq, head);
vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
ubuf->callback = vhost_zerocopy_callback;
@@ -927,7 +926,8 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
err = sock->ops->sendmsg(sock, &msg, len);
if (unlikely(err < 0)) {
if (zcopy_used) {
- vhost_net_ubuf_put(ubufs);
+ if (vq->heads[ubuf->desc].len == VHOST_DMA_IN_PROGRESS)
+ vhost_net_ubuf_put(ubufs);
nvq->upend_idx = ((unsigned)nvq->upend_idx - 1)
% UIO_MAXIOV;
}
--
2.23.0
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