[PATCH v2] net/unix: sk_socket can disappear when state is unlocked

From: Mark Salyzyn
Date: Fri May 22 2015 - 11:01:34 EST


got a rare NULL pointer dereference in clear_bit

Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx>
----
v2: switch to sock_flag(sk, SOCK_DEAD) and added net/caif/caif_socket.c

net/caif/caif_socket.c | 4 ++++
net/unix/af_unix.c | 4 ++++
2 files changed, 8 insertions(+)

diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 4ec0c80..8f44c38 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -330,6 +330,10 @@ static long caif_stream_data_wait(struct sock *sk, long timeo)
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
+
+ if (sock_flag(sk, SOCK_DEAD))
+ break;
+
clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
}

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 5266ea7..7b68dc8 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1880,6 +1880,10 @@ static long unix_stream_data_wait(struct sock *sk, long timeo,
unix_state_unlock(sk);
timeo = freezable_schedule_timeout(timeo);
unix_state_lock(sk);
+
+ if (sock_flag(sk, SOCK_DEAD))
+ break;
+
clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
}

--
2.2.0.rc0.207.ga3a616c

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/