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Subject[48/74] ax25: netrom: rose: Fix timer oopses
2.6.32-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Jarek Poplawski <jarkao2@gmail.com>

[ Upstream commit d00c362f1b0ff54161e0a42b4554ac621a9ef92d ]

Wrong ax25_cb refcounting in ax25_send_frame() and by its callers can
cause timer oopses (first reported with 2.6.29.6 kernel).

Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=14905

Reported-by: Bernard Pidoux <bpidoux@free.fr>
Tested-by: Bernard Pidoux <bpidoux@free.fr>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
include/net/netrom.h | 2 ++
net/ax25/ax25_out.c | 6 ++++++
net/netrom/nr_route.c | 11 ++++++-----
net/rose/rose_link.c | 8 ++++++++
net/rose/rose_route.c | 5 +++++
5 files changed, 27 insertions(+), 5 deletions(-)
--- a/include/net/netrom.h
+++ b/include/net/netrom.h
@@ -132,6 +132,8 @@ static __inline__ void nr_node_put(struc
static __inline__ void nr_neigh_put(struct nr_neigh *nr_neigh)
{
if (atomic_dec_and_test(&nr_neigh->refcount)) {
+ if (nr_neigh->ax25)
+ ax25_cb_put(nr_neigh->ax25);
kfree(nr_neigh->digipeat);
kfree(nr_neigh);
}
--- a/net/ax25/ax25_out.c
+++ b/net/ax25/ax25_out.c
@@ -92,6 +92,12 @@ ax25_cb *ax25_send_frame(struct sk_buff
#endif
}

+ /*
+ * There is one ref for the state machine; a caller needs
+ * one more to put it back, just like with the existing one.
+ */
+ ax25_cb_hold(ax25);
+
ax25_cb_add(ax25);

ax25->state = AX25_STATE_1;
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -842,12 +842,13 @@ int nr_route_frame(struct sk_buff *skb,
dptr = skb_push(skb, 1);
*dptr = AX25_P_NETROM;

- ax25s = ax25_send_frame(skb, 256, (ax25_address *)dev->dev_addr, &nr_neigh->callsign, nr_neigh->digipeat, nr_neigh->dev);
- if (nr_neigh->ax25 && ax25s) {
- /* We were already holding this ax25_cb */
+ ax25s = nr_neigh->ax25;
+ nr_neigh->ax25 = ax25_send_frame(skb, 256,
+ (ax25_address *)dev->dev_addr,
+ &nr_neigh->callsign,
+ nr_neigh->digipeat, nr_neigh->dev);
+ if (ax25s)
ax25_cb_put(ax25s);
- }
- nr_neigh->ax25 = ax25s;

dev_put(dev);
ret = (nr_neigh->ax25 != NULL);
--- a/net/rose/rose_link.c
+++ b/net/rose/rose_link.c
@@ -101,13 +101,17 @@ static void rose_t0timer_expiry(unsigned
static int rose_send_frame(struct sk_buff *skb, struct rose_neigh *neigh)
{
ax25_address *rose_call;
+ ax25_cb *ax25s;

if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
rose_call = (ax25_address *)neigh->dev->dev_addr;
else
rose_call = &rose_callsign;

+ ax25s = neigh->ax25;
neigh->ax25 = ax25_send_frame(skb, 260, rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
+ if (ax25s)
+ ax25_cb_put(ax25s);

return (neigh->ax25 != NULL);
}
@@ -120,13 +124,17 @@ static int rose_send_frame(struct sk_buf
static int rose_link_up(struct rose_neigh *neigh)
{
ax25_address *rose_call;
+ ax25_cb *ax25s;

if (ax25cmp(&rose_callsign, &null_ax25_address) == 0)
rose_call = (ax25_address *)neigh->dev->dev_addr;
else
rose_call = &rose_callsign;

+ ax25s = neigh->ax25;
neigh->ax25 = ax25_find_cb(rose_call, &neigh->callsign, neigh->digipeat, neigh->dev);
+ if (ax25s)
+ ax25_cb_put(ax25s);

return (neigh->ax25 != NULL);
}
--- a/net/rose/rose_route.c
+++ b/net/rose/rose_route.c
@@ -234,6 +234,8 @@ static void rose_remove_neigh(struct ros

if ((s = rose_neigh_list) == rose_neigh) {
rose_neigh_list = rose_neigh->next;
+ if (rose_neigh->ax25)
+ ax25_cb_put(rose_neigh->ax25);
kfree(rose_neigh->digipeat);
kfree(rose_neigh);
return;
@@ -242,6 +244,8 @@ static void rose_remove_neigh(struct ros
while (s != NULL && s->next != NULL) {
if (s->next == rose_neigh) {
s->next = rose_neigh->next;
+ if (rose_neigh->ax25)
+ ax25_cb_put(rose_neigh->ax25);
kfree(rose_neigh->digipeat);
kfree(rose_neigh);
return;
@@ -810,6 +814,7 @@ void rose_link_failed(ax25_cb *ax25, int

if (rose_neigh != NULL) {
rose_neigh->ax25 = NULL;
+ ax25_cb_put(ax25);

rose_del_route_by_neigh(rose_neigh);
rose_kill_by_neigh(rose_neigh);



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