summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorJames Chapman <jchapman@katalix.com>2008-12-17 12:02:16 +0000
committerDavid S. Miller <davem@davemloft.net>2008-12-18 19:41:42 -0800
commit739840d529eb7505d3cbfe9d468bf1440c9a8e27 (patch)
tree432ffe292f8886a63f1328e6e2466c01dbe452d5 /drivers
parent1b08534e562dae7b084326f8aa8cc12a4c1b6593 (diff)
downloadconfigs-739840d529eb7505d3cbfe9d468bf1440c9a8e27.tar.gz
ppp: fix segfaults introduced by netdev_priv changes
This patch fixes a segfault in ppp_shutdown_interface() and ppp_destroy_interface() when a PPP connection is closed. I bisected the problem to the following commit: commit c8019bf3aff653cceb64f66489fc299ee5957b57 Author: Wang Chen <wangchen@cn.fujitsu.com> Date: Thu Nov 20 04:24:17 2008 -0800 netdevice ppp: Convert directly reference of netdev->priv 1. Use netdev_priv(dev) to replace dev->priv. 2. Alloc netdev's private data by alloc_netdev(). Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net> The original ppp_generic code treated the netdev and struct ppp as independent data structures which were freed separately. In moving the ppp struct into the netdev, it is now possible for the private data to be freed before the call to ppp_shutdown_interface(), which is bad. The kfree(ppp) in ppp_destroy_interface() is also wrong; presumably ppp hasn't worked since the above commit. The following patch fixes both problems. Signed-off-by: James Chapman <jchapman@katalix.com> Reviewed-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ppp_generic.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 7e857e938ad..714a23035de 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -116,6 +116,7 @@ struct ppp {
unsigned long last_xmit; /* jiffies when last pkt sent 9c */
unsigned long last_recv; /* jiffies when last pkt rcvd a0 */
struct net_device *dev; /* network interface device a4 */
+ int closing; /* is device closing down? a8 */
#ifdef CONFIG_PPP_MULTILINK
int nxchan; /* next channel to send something on */
u32 nxseq; /* next sequence number to send */
@@ -995,7 +996,7 @@ ppp_xmit_process(struct ppp *ppp)
struct sk_buff *skb;
ppp_xmit_lock(ppp);
- if (ppp->dev) {
+ if (!ppp->closing) {
ppp_push(ppp);
while (!ppp->xmit_pending
&& (skb = skb_dequeue(&ppp->file.xq)))
@@ -1463,8 +1464,7 @@ static inline void
ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)
{
ppp_recv_lock(ppp);
- /* ppp->dev == 0 means interface is closing down */
- if (ppp->dev)
+ if (!ppp->closing)
ppp_receive_frame(ppp, skb, pch);
else
kfree_skb(skb);
@@ -2498,18 +2498,16 @@ init_ppp_file(struct ppp_file *pf, int kind)
*/
static void ppp_shutdown_interface(struct ppp *ppp)
{
- struct net_device *dev;
-
mutex_lock(&all_ppp_mutex);
- ppp_lock(ppp);
- dev = ppp->dev;
- ppp->dev = NULL;
- ppp_unlock(ppp);
/* This will call dev_close() for us. */
- if (dev) {
- unregister_netdev(dev);
- free_netdev(dev);
- }
+ ppp_lock(ppp);
+ if (!ppp->closing) {
+ ppp->closing = 1;
+ ppp_unlock(ppp);
+ unregister_netdev(ppp->dev);
+ } else
+ ppp_unlock(ppp);
+
cardmap_set(&all_ppp_units, ppp->file.index, NULL);
ppp->file.dead = 1;
ppp->owner = NULL;
@@ -2554,7 +2552,7 @@ static void ppp_destroy_interface(struct ppp *ppp)
if (ppp->xmit_pending)
kfree_skb(ppp->xmit_pending);
- kfree(ppp);
+ free_netdev(ppp->dev);
}
/*
@@ -2616,7 +2614,7 @@ ppp_connect_channel(struct channel *pch, int unit)
if (pch->file.hdrlen > ppp->file.hdrlen)
ppp->file.hdrlen = pch->file.hdrlen;
hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */
- if (ppp->dev && hdrlen > ppp->dev->hard_header_len)
+ if (hdrlen > ppp->dev->hard_header_len)
ppp->dev->hard_header_len = hdrlen;
list_add_tail(&pch->clist, &ppp->channels);
++ppp->n_channels;