From d00c362f1b0ff54161e0a42b4554ac621a9ef92d Mon Sep 17 00:00:00 2001 From: Jarek Poplawski Date: Sat, 16 Jan 2010 01:04:04 -0800 Subject: [PATCH] ax25: netrom: rose: Fix timer oopses 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 Tested-by: Bernard Pidoux Signed-off-by: Jarek Poplawski Signed-off-by: David S. Miller --- 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(-) diff --git a/include/net/netrom.h b/include/net/netrom.h index 15696b1fd30f..ab170a60e7d3 100644 --- a/include/net/netrom.h +++ b/include/net/netrom.h @@ -132,6 +132,8 @@ static __inline__ void nr_node_put(struct nr_node *nr_node) 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); } diff --git a/net/ax25/ax25_out.c b/net/ax25/ax25_out.c index bf706f83a5c9..14912600ec57 100644 --- a/net/ax25/ax25_out.c +++ b/net/ax25/ax25_out.c @@ -92,6 +92,12 @@ ax25_cb *ax25_send_frame(struct sk_buff *skb, int paclen, ax25_address *src, ax2 #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; diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c index aacba76070fc..e2e2d33cafdf 100644 --- a/net/netrom/nr_route.c +++ b/net/netrom/nr_route.c @@ -843,12 +843,13 @@ int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25) 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); diff --git a/net/rose/rose_link.c b/net/rose/rose_link.c index bd86a63960ce..5ef5f6988a2e 100644 --- a/net/rose/rose_link.c +++ b/net/rose/rose_link.c @@ -101,13 +101,17 @@ static void rose_t0timer_expiry(unsigned long param) 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_buff *skb, struct rose_neigh *neigh) 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); } diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index 795c4b025e31..70a0b3b4b4d2 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -235,6 +235,8 @@ static void rose_remove_neigh(struct rose_neigh *rose_neigh) 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; @@ -243,6 +245,8 @@ static void rose_remove_neigh(struct rose_neigh *rose_neigh) 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; @@ -812,6 +816,7 @@ void rose_link_failed(ax25_cb *ax25, int reason) 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); -- GitLab