diff options
| author | Andrew Melnychenko <andrew@daynix.com> | 2024-01-15 21:48:40 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2024-03-19 02:45:49 -0400 |
| commit | f6baca2d32ead51b10e15f1eef812d7c6a7b9a40 (patch) | |
| tree | 301e9d942436f868eb632538192b71b5375f68fa /drivers/vhost | |
| parent | e8f897f4afef0031fe618a8e94127a0934896aba (diff) | |
| download | lwn-f6baca2d32ead51b10e15f1eef812d7c6a7b9a40.tar.gz lwn-f6baca2d32ead51b10e15f1eef812d7c6a7b9a40.zip | |
vhost: Added pad cleanup if vnet_hdr is not present.
When the Qemu launched with vhost but without tap vnet_hdr,
vhost tries to copy vnet_hdr from socket iter with size 0
to the page that may contain some trash.
That trash can be interpreted as unpredictable values for
vnet_hdr.
That leads to dropping some packets and in some cases to
stalling vhost routine when the vhost_net tries to process
packets and fails in a loop.
Qemu options:
-netdev tap,vhost=on,vnet_hdr=off,...
Signed-off-by: Andrew Melnychenko <andrew@daynix.com>
Message-Id: <20240115194840.1183077-1-andrew@daynix.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/net.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index f2ed7167c848..57411ac2d08b 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -735,6 +735,9 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue *nvq, hdr = buf; gso = &hdr->gso; + if (!sock_hlen) + memset(buf, 0, pad); + if ((gso->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && vhost16_to_cpu(vq, gso->csum_start) + vhost16_to_cpu(vq, gso->csum_offset) + 2 > |