On 10/29/20 8:38 AM, Markus Armbruster wrote:
> Commit 776b97d360 "qemu-sockets: add abstract UNIX domain socket
> support" neglected to update socket_sockaddr_to_address_unix(). The
> function returns a non-abstract socket address for abstract
> sockets (wrong) with a null @path (also wrong; a non-optional QAPI str
> member must never be null).
>
> The null @path is due to confused code going back all the way to
> commit 17c55decec "sockets: add helpers for creating SocketAddress
> from a socket".
>
> Add the required special case, and simplify the confused code.
>
> Fixes: 776b97d3605ed0fc94443048fdf988c7725e38a9
> Signed-off-by: Markus Armbruster <arm...@redhat.com>
> ---
> util/qemu-sockets.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
> index c802d5aa0a..801c5e3957 100644
> --- a/util/qemu-sockets.c
> +++ b/util/qemu-sockets.c
> @@ -1264,10 +1264,20 @@ socket_sockaddr_to_address_unix(struct
> sockaddr_storage *sa,
>
> addr = g_new0(SocketAddress, 1);
> addr->type = SOCKET_ADDRESS_TYPE_UNIX;
> - if (su->sun_path[0]) {
> - addr->u.q_unix.path = g_strndup(su->sun_path, sizeof(su->sun_path));
> +#ifdef CONFIG_LINUX
> + if (!su->sun_path[0]) {
> + /* Linux abstract socket */
> + addr->u.q_unix.path = g_strndup(su->sun_path + 1,
> + sizeof(su->sun_path) - 1);
> + addr->u.q_unix.has_abstract = true;
> + addr->u.q_unix.abstract = true;
> + addr->u.q_unix.has_tight = true;
> + addr->u.q_unix.tight = !su->sun_path[sizeof(su->sun_path) - 1];
This is questionable - how can you tell from the last byte whether the
name was created as tight or not?
> + return addr;
> }
> +#endif
>
> + addr->u.q_unix.path = g_strdup(su->sun_path);
This is wrong on at least Linux, where su->sun_path need not be
NUL-terminated (allowing file-system Unix sockets to have one more byte
in their name); you need the strndup that you replaced above, in order
avoid reading beyond the end of the array.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
