From: Wei Yang unix_release_sock() drains sk_receive_queue in a tight loop with no rescheduling point. Each iteration may do extra work depending on the socket type: kfree_skb() runs unix_destruct_scm()->fput() for SCM_RIGHTS fds on data sockets, and a LISTEN socket recurses into unix_release_sock() for each embryonic child. A long receive queue can hog the CPU and trip the softlockup watchdog on CONFIG_PREEMPT_NONE kernels. We have reproduced this multiple times under stress-ng stress testing. Add cond_resched() as done in similar teardown loops (inet_csk_listen_stop, inet_twsk_purge, close_files). Signed-off-by: Wei Yang --- net/unix/af_unix.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index f7a9d55eee8a..8b4624ce4178 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -724,6 +724,7 @@ static void unix_release_sock(struct sock *sk, int embrion) /* passed fds are erased in the kfree_skb hook */ kfree_skb_reason(skb, SKB_DROP_REASON_SOCKET_CLOSE); + cond_resched(); } if (path.dentry) -- 2.43.5