Commit 772f0104 authored Jul 02, 2025 by Kuniyuki Iwashima Committed by Jakub Kicinski Jul 08, 2025

af_unix: Don't check SOCK_DEAD in unix_stream_read_skb().



unix_stream_read_skb() checks SOCK_DEAD only when the dequeued skb is
OOB skb.

unix_stream_read_skb() is called for a SOCK_STREAM socket in SOCKMAP
when data is sent to it.

The function is invoked via sk_psock_verdict_data_ready(), which is
set to sk->sk_data_ready().

During sendmsg(), we check if the receiver has SOCK_DEAD, so there
is no point in checking it again later in ->read_skb().

Also, unix_read_skb() for SOCK_DGRAM does not have the test either.

Let's remove the SOCK_DEAD test in unix_stream_read_skb().

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250702223606.1054680-3-kuniyu@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent b429a5ad

net/unix/af_unix.c

+0 −10

Original line number	Diff line number	Diff line
		@@ -2803,14 +2803,6 @@ static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
		if (unlikely(skb == READ_ONCE(u->oob_skb))) {
		bool drop = false;

		unix_state_lock(sk);

		if (sock_flag(sk, SOCK_DEAD)) {
		unix_state_unlock(sk);
		kfree_skb_reason(skb, SKB_DROP_REASON_SOCKET_CLOSE);
		return -ECONNRESET;
		}

		spin_lock(&sk->sk_receive_queue.lock);
		if (likely(skb == u->oob_skb)) {
		WRITE_ONCE(u->oob_skb, NULL);
		@@ -2818,8 +2810,6 @@ static int unix_stream_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
		}
		spin_unlock(&sk->sk_receive_queue.lock);

		unix_state_unlock(sk);

		if (drop) {
		kfree_skb_reason(skb, SKB_DROP_REASON_UNIX_SKIP_OOB);
		return -EAGAIN;