net: unix: allow set_peek_off to fail

[ Upstream commit 12663bfc97c8b3fdb292428105dd92d563164050 ]

unix_dgram_recvmsg() will hold the readlock of the socket until recv
is complete.

In the same time, we may try to setsockopt(SO_PEEK_OFF) which will hang until
unix_dgram_recvmsg() will complete (which can take a while) without allowing
us to break out of it, triggering a hung task spew.

Instead, allow set_peek_off to fail, this way userspace will not hang.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/net.h b/include/linux/net.h
index 0c4ae5d94de9..65545ac6fb9c 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -180,7 +180,7 @@ struct proto_ops {
                                       int offset, size_t size, int flags);
         ssize_t         (*splice_read)(struct socket *sock,  loff_t *ppos,
                                        struct pipe_inode_info *pipe, size_t len, unsigned int flags);
-        void            (*set_peek_off)(struct sock *sk, int val);
+        int             (*set_peek_off)(struct sock *sk, int val);
 };
 
 #define DECLARE_SOCKADDR(type, dst, src)        \