Commit 9905eed4 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'af_unix-OOB-fixes' 

Kuniyuki Iwashima says:

====================
af_unix: Fix some OOB implementation.

This series fixes some data-races and adds a missing feature around the
commit 314001f0 ("af_unix: Add OOB support").

Changelog:
  - v3:
    - Add the first patch

  - v2: https://lore.kernel.org/netdev/20220315054801.72035-1-kuniyu@amazon.co.jp/
    - Add READ_ONCE() to avoid a race reported by KCSAN (Eric)
    - Add IS_ENABLED(CONFIG_AF_UNIX_OOB) (Shoaib)

  - v1: https://lore.kernel.org/netdev/20220314052110.53634-1-kuniyu@amazon.co.jp/


====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 4219196d d9a232d4

net/unix/af_unix.c

+9 −7
Original line number Diff line number Diff line
@@ -2084,7 +2084,7 @@ static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other 
	if (ousk->oob_skb)

		consume_skb(ousk->oob_skb);



	ousk->oob_skb = skb;

	WRITE_ONCE(ousk->oob_skb, skb);



	scm_stat_add(other, skb);

	skb_queue_tail(&other->sk_receive_queue, skb);
@@ -2602,9 +2602,8 @@ static int unix_stream_recv_urg(struct unix_stream_read_state *state) 


	oob_skb = u->oob_skb;



	if (!(state->flags & MSG_PEEK)) {

		u->oob_skb = NULL;

	}

	if (!(state->flags & MSG_PEEK))

		WRITE_ONCE(u->oob_skb, NULL);



	unix_state_unlock(sk);
@@ -2639,7 +2638,7 @@ static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, 
				skb = NULL;

			} else if (sock_flag(sk, SOCK_URGINLINE)) {

				if (!(flags & MSG_PEEK)) {

					u->oob_skb = NULL;

					WRITE_ONCE(u->oob_skb, NULL);

					consume_skb(skb);

				}

			} else if (!(flags & MSG_PEEK)) {
@@ -3094,11 +3093,10 @@ static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) 
	case SIOCATMARK:

		{

			struct sk_buff *skb;

			struct unix_sock *u = unix_sk(sk);

			int answ = 0;



			skb = skb_peek(&sk->sk_receive_queue);

			if (skb && skb == u->oob_skb)

			if (skb && skb == READ_ONCE(unix_sk(sk)->oob_skb))

				answ = 1;

			err = put_user(answ, (int __user *)arg);

		}
@@ -3139,6 +3137,10 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa 
		mask |= EPOLLIN | EPOLLRDNORM;

	if (sk_is_readable(sk))

		mask |= EPOLLIN | EPOLLRDNORM;

#if IS_ENABLED(CONFIG_AF_UNIX_OOB)

	if (READ_ONCE(unix_sk(sk)->oob_skb))

		mask |= EPOLLPRI;

#endif



	/* Connection-based need to check for termination and startup */

	if ((sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) &&

tools/testing/selftests/net/af_unix/test_unix_oob.c

+3 −3
Original line number Diff line number Diff line
@@ -218,10 +218,10 @@ main(int argc, char **argv) 


	/* Test 1:

	 * veriyf that SIGURG is

	 * delivered and 63 bytes are

	 * read and oob is '@'

	 * delivered, 63 bytes are

	 * read, oob is '@', and POLLPRI works.

	 */

	wait_for_data(pfd, POLLIN | POLLPRI);

	wait_for_data(pfd, POLLPRI);

	read_oob(pfd, &oob);

	len = read_data(pfd, buf, 1024);

	if (!signal_recvd || len != 63 || oob != '@') {