If fortify is enabled, it will generate a warning if memcpy src is NULL even if size is zero. This happens if the MP message sync is called with no file descriptors.
Bugzilla ID 1446 Fixes: 6a84c37e3975 ("net/virtio-user: add vhost-user adapter layer") Signed-off-by: Stephen Hemminger <step...@networkplumber.org> --- drivers/net/virtio/virtio_user/vhost_user.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c index 3c05ac9cc0..c10252506b 100644 --- a/drivers/net/virtio/virtio_user/vhost_user.c +++ b/drivers/net/virtio/virtio_user/vhost_user.c @@ -128,7 +128,8 @@ vhost_user_write(int fd, struct vhost_user_msg *msg, int *fds, int fd_num) cmsg->cmsg_len = CMSG_LEN(fd_size); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; - memcpy(CMSG_DATA(cmsg), fds, fd_size); + if (fd_size > 0) + memcpy(CMSG_DATA(cmsg), fds, fd_size); do { r = sendmsg(fd, &msgh, 0); -- 2.43.0