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| author | Sasha Levin <sasha.levin@oracle.com> | 2013-12-07 17:26:27 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-15 15:27:11 -0800 |
| commit | e387172fe3c3f5d256f183c0f88c9f0dc5434a88 (patch) | |
| tree | 2869b0c303eb867b899857588ab9bf9a9f8c9f78 | |
| parent | fcbb1132558f68da2ce37a883be165129aa1eb31 (diff) | |
| download | lwn-e387172fe3c3f5d256f183c0f88c9f0dc5434a88.tar.gz lwn-e387172fe3c3f5d256f183c0f88c9f0dc5434a88.zip | |
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>
| -rw-r--r-- | include/linux/net.h | 2 | ||||
| -rw-r--r-- | net/core/sock.c | 2 | ||||
| -rw-r--r-- | net/unix/af_unix.c | 8 |
3 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/net.h b/include/linux/net.h index 45232814fc03..ff8097592f1d 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -215,7 +215,7 @@ 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) \ diff --git a/net/core/sock.c b/net/core/sock.c index 561eb57f590c..832cf043a8f7 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -795,7 +795,7 @@ set_rcvbuf: case SO_PEEK_OFF: if (sock->ops->set_peek_off) - sock->ops->set_peek_off(sk, val); + ret = sock->ops->set_peek_off(sk, val); else ret = -EOPNOTSUPP; break; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 0540dd9b0387..8519968f487f 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -524,13 +524,17 @@ static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *, static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *, struct msghdr *, size_t, int); -static void unix_set_peek_off(struct sock *sk, int val) +static int unix_set_peek_off(struct sock *sk, int val) { struct unix_sock *u = unix_sk(sk); - mutex_lock(&u->readlock); + if (mutex_lock_interruptible(&u->readlock)) + return -EINTR; + sk->sk_peek_off = val; mutex_unlock(&u->readlock); + + return 0; } |