[PATCH] virtiofsd: Fix potential NULL pointer dereference in virtio_send_msg()

[Alex Chen]

The 'ch' will be NULL in the following stack:
send_notify_iov()->fuse_send_msg()->virtio_send_msg(),
so we should check 'ch' is valid before dereferencing it

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Alex Chen <alex.chen@huawei.com>
---
 tools/virtiofsd/fuse_virtio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
index 623812c432..31b2187a15 100644
--- a/tools/virtiofsd/fuse_virtio.c
+++ b/tools/virtiofsd/fuse_virtio.c
@@ -205,6 +205,8 @@ static void copy_iov(struct iovec *src_iov, int src_count,
 int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch,
                     struct iovec *iov, int count)
 {
+    assert(ch);
+
     FVRequest *req = container_of(ch, FVRequest, ch);
     struct fv_QueueInfo *qi = ch->qi;
     VuDev *dev = &se->virtio_dev->dev;
-- 
2.19.1