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authorErik Hugne <erik.hugne@ericsson.com>2014-03-24 16:56:38 +0100
committerDavid S. Miller <davem@davemloft.net>2014-03-24 15:36:56 -0400
commita5d0e7c037119484a7006b883618bfa87996cb41 (patch)
tree0240143aaed7d20be2d7198393e4f5c1e4b4f681 /net
parent4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa (diff)
downloadlinux-linaro-stable-a5d0e7c037119484a7006b883618bfa87996cb41.tar.gz
tipc: fix spinlock recursion bug for failed subscriptions
If a topology event subscription fails for any reason, such as out of memory, max number reached or because we received an invalid request the correct behavior is to terminate the subscribers connection to the topology server. This is currently broken and produces the following oops: [27.953662] tipc: Subscription rejected, illegal request [27.955329] BUG: spinlock recursion on CPU#1, kworker/u4:0/6 [27.957066] lock: 0xffff88003c67f408, .magic: dead4ead, .owner: kworker/u4:0/6, .owner_cpu: 1 [27.958054] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 3.14.0-rc6+ #5 [27.960230] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [27.960874] Workqueue: tipc_rcv tipc_recv_work [tipc] [27.961430] ffff88003c67f408 ffff88003de27c18 ffffffff815c0207 ffff88003de1c050 [27.962292] ffff88003de27c38 ffffffff815beec5 ffff88003c67f408 ffffffff817f0a8a [27.963152] ffff88003de27c58 ffffffff815beeeb ffff88003c67f408 ffffffffa0013520 [27.964023] Call Trace: [27.964292] [<ffffffff815c0207>] dump_stack+0x45/0x56 [27.964874] [<ffffffff815beec5>] spin_dump+0x8c/0x91 [27.965420] [<ffffffff815beeeb>] spin_bug+0x21/0x26 [27.965995] [<ffffffff81083df6>] do_raw_spin_lock+0x116/0x140 [27.966631] [<ffffffff815c6215>] _raw_spin_lock_bh+0x15/0x20 [27.967256] [<ffffffffa0008540>] subscr_conn_shutdown_event+0x20/0xa0 [tipc] [27.968051] [<ffffffffa000fde4>] tipc_close_conn+0xa4/0xb0 [tipc] [27.968722] [<ffffffffa00101ba>] tipc_conn_terminate+0x1a/0x30 [tipc] [27.969436] [<ffffffffa00089a2>] subscr_conn_msg_event+0x1f2/0x2f0 [tipc] [27.970209] [<ffffffffa0010000>] tipc_receive_from_sock+0x90/0xf0 [tipc] [27.970972] [<ffffffffa000fa79>] tipc_recv_work+0x29/0x50 [tipc] [27.971633] [<ffffffff8105dbf5>] process_one_work+0x165/0x3e0 [27.972267] [<ffffffff8105e869>] worker_thread+0x119/0x3a0 [27.972896] [<ffffffff8105e750>] ? manage_workers.isra.25+0x2a0/0x2a0 [27.973622] [<ffffffff810648af>] kthread+0xdf/0x100 [27.974168] [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0 [27.974893] [<ffffffff815ce13c>] ret_from_fork+0x7c/0xb0 [27.975466] [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0 The recursion occurs when subscr_terminate tries to grab the subscriber lock, which is already taken by subscr_conn_msg_event. We fix this by checking if the request to establish a new subscription was successful, and if not we initiate termination of the subscriber after we have released the subscriber lock. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/tipc/subscr.c29
1 files changed, 15 insertions, 14 deletions
diff --git a/net/tipc/subscr.c b/net/tipc/subscr.c
index 11c9ae00837d..642437231ad5 100644
--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -263,9 +263,9 @@ static void subscr_cancel(struct tipc_subscr *s,
*
* Called with subscriber lock held.
*/
-static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
- struct tipc_subscriber *subscriber)
-{
+static int subscr_subscribe(struct tipc_subscr *s,
+ struct tipc_subscriber *subscriber,
+ struct tipc_subscription **sub_p) {
struct tipc_subscription *sub;
int swap;
@@ -276,23 +276,21 @@ static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
subscr_cancel(s, subscriber);
- return NULL;
+ return 0;
}
/* Refuse subscription if global limit exceeded */
if (atomic_read(&subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
pr_warn("Subscription rejected, limit reached (%u)\n",
TIPC_MAX_SUBSCRIPTIONS);
- subscr_terminate(subscriber);
- return NULL;
+ return -EINVAL;
}
/* Allocate subscription object */
sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
if (!sub) {
pr_warn("Subscription rejected, no memory\n");
- subscr_terminate(subscriber);
- return NULL;
+ return -ENOMEM;
}
/* Initialize subscription object */
@@ -306,8 +304,7 @@ static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
(sub->seq.lower > sub->seq.upper)) {
pr_warn("Subscription rejected, illegal request\n");
kfree(sub);
- subscr_terminate(subscriber);
- return NULL;
+ return -EINVAL;
}
INIT_LIST_HEAD(&sub->nameseq_list);
list_add(&sub->subscription_list, &subscriber->subscription_list);
@@ -320,8 +317,8 @@ static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
(Handler)subscr_timeout, (unsigned long)sub);
k_start_timer(&sub->timer, sub->timeout);
}
-
- return sub;
+ *sub_p = sub;
+ return 0;
}
/* Handle one termination request for the subscriber */
@@ -335,10 +332,14 @@ static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
void *usr_data, void *buf, size_t len)
{
struct tipc_subscriber *subscriber = usr_data;
- struct tipc_subscription *sub;
+ struct tipc_subscription *sub = NULL;
spin_lock_bh(&subscriber->lock);
- sub = subscr_subscribe((struct tipc_subscr *)buf, subscriber);
+ if (subscr_subscribe((struct tipc_subscr *)buf, subscriber, &sub) < 0) {
+ spin_unlock_bh(&subscriber->lock);
+ subscr_terminate(subscriber);
+ return;
+ }
if (sub)
tipc_nametbl_subscribe(sub);
spin_unlock_bh(&subscriber->lock);