Re: [Qemu-devel] [PATCH] qemu-nbd: Fix coverity issues

[Markus Armbruster <armbru@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> There are two issues in qemu-nbd: a missing return value check after
> calling accept(), and file descriptor leaks in nbd_client_thread.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  qemu-nbd.c | 17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/qemu-nbd.c b/qemu-nbd.c
> index bdac1f3..899e67c 100644
> --- a/qemu-nbd.c
> +++ b/qemu-nbd.c
> @@ -288,19 +288,19 @@ static void *nbd_client_thread(void *arg)
>      ret = nbd_receive_negotiate(sock, NULL, &nbdflags,
>                                  &size, &blocksize);
>      if (ret < 0) {
> -        goto out;
> +        goto out_socket;
>      }
>  
>      fd = open(device, O_RDWR);
>      if (fd < 0) {
>          /* Linux-only, we can use %m in printf.  */
>          fprintf(stderr, "Failed to open %s: %m", device);
> -        goto out;
> +        goto out_socket;
>      }
>  
>      ret = nbd_init(fd, sock, nbdflags, size, blocksize);
>      if (ret < 0) {
> -        goto out;
> +        goto out_fd;
>      }
>  
>      /* update partition table */
> @@ -316,12 +316,16 @@ static void *nbd_client_thread(void *arg)
>  
>      ret = nbd_client(fd);
>      if (ret) {
> -        goto out;
> +        goto out_fd;
>      }
>      close(fd);
>      kill(getpid(), SIGTERM);
>      return (void *) EXIT_SUCCESS;
>  
> +out_fd:
> +    close(fd);
> +out_socket:
> +    closesocket(sock);
>  out:
>      kill(getpid(), SIGTERM);
>      return (void *) EXIT_FAILURE;

The return values are disgusting, but that's not your fault.  Hmm,
actually it is: commit a517e88b.

> @@ -355,6 +359,11 @@ static void nbd_accept(void *opaque)
>      socklen_t addr_len = sizeof(addr);
>  
>      int fd = accept(server_fd, (struct sockaddr *)&addr, &addr_len);
> +    if (fd < 0) {
> +        perror("accept");
> +        return;
> +    }
> +
>      if (state >= TERMINATE) {
>          close(fd);
>          return;

Reviewed-by: Markus Armbruster <armbru@redhat.com>