From: Daan De Meyer <daan.j.demeyer@xxxxxxxxx>
Date: Thu, 12 Oct 2023 10:52:13 +0200
> Changes since v1:
>
> * Added missing Signed-off-by tag
You can put these after --- so that it will disappear when merged.
>
> We should not run the recvmsg() hooks on unnamed sockets as we do
> not run them on unnamed sockets in the other hooks either. We may
> look into relaxing this later but for now let's make sure we are
> consistent and not run the hooks on unnamed sockets anywhere.
>
> Signed-off-by: Daan De Meyer <daan.j.demeyer@xxxxxxxxx>
> ---
> net/unix/af_unix.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index e10d07c76044..81fb8bddaff9 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -2416,9 +2416,10 @@ int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
> if (msg->msg_name) {
> unix_copy_addr(msg, skb->sk);
How is an unnamed socket set to skb->sk ?
>
> - BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk,
> - msg->msg_name,
> - &msg->msg_namelen);
> + if (msg->msg_namelen > 0)
> + BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk,
> + msg->msg_name,
> + &msg->msg_namelen);
> }
>
> if (size > skb->len - skip)
> @@ -2773,9 +2774,10 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state,
> state->msg->msg_name);
> unix_copy_addr(state->msg, skb->sk);
>
> - BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk,
> - state->msg->msg_name,
> - &state->msg->msg_namelen);
> + if (state->msg->msg_namelen > 0)
> + BPF_CGROUP_RUN_PROG_UNIX_RECVMSG_LOCK(sk,
> + state->msg->msg_name,
> + &state->msg->msg_namelen);
>
> sunaddr = NULL;
> }
> --
> 2.41.0
>
