[PATCH] appletalk: Set skb with destructor

From: Andrey Utkin
Date: Sun Jul 06 2014 - 07:58:27 EST


The sock ref counting is off so there is a kernel panic when you run
`atalkd`. See https://bugzilla.kernel.org/show_bug.cgi?id=79441
This fix is similar to 0ae89beb283a ('can: add destructor for self
generated skbs')

Reported-by: Ed Martin <edman007@xxxxxxxxxxxx>
Signed-off-by: Andrey Utkin <andrey.krieger.utkin@xxxxxxxxx>
---
net/appletalk/ddp.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 01a1082..3d8ab34 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1399,6 +1399,11 @@ drop:
return NET_RX_DROP;
}

+static inline void atalk_skb_destructor(struct sk_buff *skb)
+{
+ sock_put(skb->sk);
+}
+
/**
* atalk_rcv - Receive a packet (in skb) from device dev
* @skb - packet received
@@ -1489,6 +1494,8 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
goto drop;

/* Queue packet (standard) */
+ sock_hold(sock);
+ skb->destructor = atalk_skb_destructor;
skb->sk = sock;

if (sock_queue_rcv_skb(sock, skb) < 0)
@@ -1644,6 +1651,8 @@ static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
if (!skb)
goto out;

+ sock_hold(sk);
+ skb->destructor = atalk_skb_destructor;
skb->sk = sk;
skb_reserve(skb, ddp_dl->header_length);
skb_reserve(skb, dev->hard_header_len);
--
1.8.3.2

--
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/