From e88958e6369aeba48623afa18dd67fdf41c98d75 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
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 <penguin-kernel@i-love.sakura.ne.jp>
Fixes: a11e1d432b51 ("Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
net/socket.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/socket.c b/net/socket.c
index a564c6ed19d56..85633622c94d0 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);
}
--
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