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authorSasha Levin <sasha.levin@oracle.com>2013-12-07 17:26:27 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-01-15 15:31:34 -0800
commita84305bbc625fac01f8700c26d25c99f4d846c56 (patch)
treee84e020acef101c721954a25b4ebc2d6c2eec0a7 /net
parente7556142c6db8a3a748d597a917e84a525c1b15e (diff)
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>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock.c2
-rw-r--r--net/unix/af_unix.c8
2 files changed, 7 insertions, 3 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index 0b39e7ae4383..5cec994ee2f3 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -888,7 +888,7 @@ 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;
}