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authorGreg Kurz <groug@kaod.org>2018-01-22 22:02:05 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-22 15:43:50 +0100
commit39e0a6bd07182815062c74fc73ce0ea94578ce00 (patch)
tree307227b52cd225f46dd992ccb2b4d10f169fd1c1 /net
parentefb1cbc229f122bc1d1b5e85bdd2da971c953f2e (diff)
9p/trans_virtio: discard zero-length reply
commit 26d99834f89e76514076d9cd06f61e56e6a509b8 upstream. When a 9p request is successfully flushed, the server is expected to just mark it as used without sending a 9p reply (ie, without writing data into the buffer). In this case, virtqueue_get_buf() will return len == 0 and we must not report a REQ_STATUS_RCVD status to the client, otherwise the client will erroneously assume the request has not been flushed. Cc: stable@vger.kernel.org Signed-off-by: Greg Kurz <groug@kaod.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/9p/trans_virtio.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index f3a4efcf1456..3aa5a93ad107 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -160,7 +160,8 @@ static void req_done(struct virtqueue *vq)
spin_unlock_irqrestore(&chan->lock, flags);
/* Wakeup if anyone waiting for VirtIO ring space. */
wake_up(chan->vc_wq);
- p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
+ if (len)
+ p9_client_cb(chan->client, req, REQ_STATUS_RCVD);
}
}