From e88958e6369aeba48623afa18dd67fdf41c98d75 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 29 Jun 2018 15:37:24 +0200 Subject: [PATCH] net: handle NULL ->poll gracefully The big aio poll revert broke various network protocols that don't implement ->poll as a patch in the aio poll serie removed sock_no_poll and made the common code handle this case. Reported-by: syzbot+57727883dbad76db2ef0@syzkaller.appspotmail.com Reported-by: syzbot+cdb0d3176b53d35ad454@syzkaller.appspotmail.com Reported-by: syzbot+2c7e8f74f8b2571c87e8@syzkaller.appspotmail.com Reported-by: Tetsuo Handa Fixes: a11e1d432b51 ("Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL") Signed-off-by: Christoph Hellwig Signed-off-by: Linus Torvalds --- net/socket.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/socket.c b/net/socket.c index a564c6ed19d5..85633622c94d 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1133,6 +1133,8 @@ static __poll_t sock_poll(struct file *file, poll_table *wait) __poll_t events = poll_requested_events(wait); sock_poll_busy_loop(sock, events); + if (!sock->ops->poll) + return 0; return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock); } -- 2.30.2