af_unix: Clean up error paths in unix_dgram_sendmsg().

The error path is complicated in unix_dgram_sendmsg() because there
are two timings when other could be non-NULL: when it's fetched from
unix_peer_get() and when it's looked up by unix_find_other().

Let's move unix_peer_get() to the else branch for unix_find_other()
and clean up the error paths.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Kuniyuki Iwashima 2024-12-13 20:08:49 +09:00 committed by Paolo Abeni
parent 106d979b85
commit 62c6db251e

View File

@ -1993,12 +1993,6 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
NULL);
if (err)
goto out;
} else {
other = unix_peer_get(sk);
if (!other) {
err = -ENOTCONN;
goto out;
}
}
if ((test_bit(SOCK_PASSCRED, &sock->flags) ||
@ -2026,7 +2020,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
skb = sock_alloc_send_pskb(sk, len - data_len, data_len,
msg->msg_flags & MSG_DONTWAIT, &err,
PAGE_ALLOC_COSTLY_ORDER);
if (skb == NULL)
if (!skb)
goto out;
err = unix_scm_to_skb(&scm, skb, true);
@ -2042,13 +2036,18 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
if (!other) {
if (msg->msg_namelen) {
lookup:
other = unix_find_other(sock_net(sk), msg->msg_name,
msg->msg_namelen, sk->sk_type);
if (IS_ERR(other)) {
err = PTR_ERR(other);
other = NULL;
goto out_free;
}
} else {
other = unix_peer_get(sk);
if (!other) {
err = -ENOTCONN;
goto out_free;
}
}
@ -2056,7 +2055,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
if (sk_filter(other, skb) < 0) {
/* Toss the packet but do not return any error to the sender */
err = len;
goto out_free;
goto out_sock_put;
}
restart:
@ -2080,7 +2079,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
* unlike SOCK_DGRAM wants.
*/
err = -EPIPE;
goto out_free;
goto out_sock_put;
}
if (!sk_locked)
@ -2096,14 +2095,14 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
unix_dgram_disconnected(sk, other);
sock_put(other);
err = -ECONNREFUSED;
goto out_free;
goto out_sock_put;
}
unix_state_unlock(sk);
if (!msg->msg_namelen) {
err = -ECONNRESET;
goto out_free;
goto out_sock_put;
}
goto lookup;
@ -2132,7 +2131,7 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
err = sock_intr_errno(timeo);
if (signal_pending(current))
goto out_free;
goto out_sock_put;
goto restart;
}
@ -2173,11 +2172,11 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
if (sk_locked)
unix_state_unlock(sk);
unix_state_unlock(other);
out_sock_put:
sock_put(other);
out_free:
kfree_skb(skb);
out:
if (other)
sock_put(other);
scm_destroy(&scm);
return err;
}