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| author | Sasha Levin <sasha.levin@oracle.com> | 2013-12-07 17:26:27 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-12-10 21:45:15 -0500 |
| commit | 12663bfc97c8b3fdb292428105dd92d563164050 (patch) | |
| tree | 3cfc0b33e9c96636e397c9c19806208735556b14 | |
| parent | 88b07b3660362049769f36c94f2c5a623424c992 (diff) | |
| download | linux-12663bfc97c8b3fdb292428105dd92d563164050.tar.gz linux-12663bfc97c8b3fdb292428105dd92d563164050.tar.bz2 linux-12663bfc97c8b3fdb292428105dd92d563164050.zip | |
net: unix: allow set_peek_off to fail
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>
| -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 4bcee94cef93..69be3e6079c8 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -181,7 +181,7 @@ 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 ab20ed9b0f31..5393b4b719d7 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -882,7 +882,7 @@ 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 01625ccc3ae6..a0ca162e5bd5 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -530,13 +530,17 @@ 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; } |