Commit 1b08534e authored Dec 18, 2008 by Wei Yongjun Committed by David S. Miller Dec 18, 2008

net: Fix module refcount leak in kernel_accept()



The kernel_accept() does not hold the module refcount of newsock->ops->owner,
so we need __module_get(newsock->ops->owner) code after call kernel_accept()
by hand.
In sunrpc, the module refcount is missing to hold. So this cause kernel panic.

Used following script to reproduct:

while [ 1 ];
do
    mount -t nfs4 192.168.0.19:/ /mnt
    touch /mnt/file
    umount /mnt
    lsmod | grep ipv6
done

This patch fixed the problem by add __module_get(newsock->ops->owner) to
kernel_accept(). So we do not need to used __module_get(newsock->ops->owner)
in every place when used kernel_accept().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 3298a738

net/bluetooth/rfcomm/core.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -1786,8 +1786,6 @@ static inline void rfcomm_accept_connection(struct rfcomm_session *s)
		if (err < 0)
		return;

		__module_get(nsock->ops->owner);

		/* Set our callbacks */
		nsock->sk->sk_data_ready = rfcomm_l2data_ready;
		nsock->sk->sk_state_change = rfcomm_l2state_change;

net/socket.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -2307,6 +2307,7 @@ int kernel_accept(struct socket sock, struct socket *newsock, int flags)
		}

		(*newsock)->ops = sock->ops;
		__module_get((*newsock)->ops->owner);

		done:
		return err;