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authorErik Hugne <erik.hugne@ericsson.com>2015-04-23 09:37:40 -0400
committerDavid S. Miller <davem@davemloft.net>2015-04-23 11:50:34 -0400
commit73a317377303b5ec14d4703d73ba87efffbb779d (patch)
tree4d84c6e1de1a3edb94f21d9730b9c23fc31eb7c8 /net
parent9871b27f6705fc6e0ba633b136369a289b2bfb99 (diff)
downloadkernel-73a317377303b5ec14d4703d73ba87efffbb779d.tar.gz
tipc: fix node refcount issue
When link statistics is dumped over netlink, we iterate over the list of peer nodes and append each links statistics to the netlink msg. In the case where the dump is resumed after filling up a nlmsg, the node refcnt is decremented without having been incremented previously which may cause the node reference to be freed. When this happens, the following info/stacktrace will be generated, followed by a crash or undefined behavior. We fix this by removing the erroneous call to tipc_node_put inside the loop that iterates over nodes. [ 384.312303] INFO: trying to register non-static key. [ 384.313110] the code is fine but needs lockdep annotation. [ 384.313290] turning off the locking correctness validator. [ 384.313290] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.0.0+ #13 [ 384.313290] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 384.313290] ffff88003c6d0290 ffff88003cc03ca8 ffffffff8170adf1 0000000000000007 [ 384.313290] ffffffff82728730 ffff88003cc03d38 ffffffff810a6a6d 00000000001d7200 [ 384.313290] ffff88003c6d0ab0 ffff88003cc03ce8 0000000000000285 0000000000000001 [ 384.313290] Call Trace: [ 384.313290] <IRQ> [<ffffffff8170adf1>] dump_stack+0x4c/0x65 [ 384.313290] [<ffffffff810a6a6d>] __lock_acquire+0xf3d/0xf50 [ 384.313290] [<ffffffff810a7375>] lock_acquire+0xd5/0x290 [ 384.313290] [<ffffffffa0043e8c>] ? link_timeout+0x1c/0x170 [tipc] [ 384.313290] [<ffffffffa0043e70>] ? link_state_event+0x4e0/0x4e0 [tipc] [ 384.313290] [<ffffffff81712890>] _raw_spin_lock_bh+0x40/0x80 [ 384.313290] [<ffffffffa0043e8c>] ? link_timeout+0x1c/0x170 [tipc] [ 384.313290] [<ffffffffa0043e8c>] link_timeout+0x1c/0x170 [tipc] [ 384.313290] [<ffffffff810c4698>] call_timer_fn+0xb8/0x490 [ 384.313290] [<ffffffff810c45e0>] ? process_timeout+0x10/0x10 [ 384.313290] [<ffffffff810c5a2c>] run_timer_softirq+0x21c/0x420 [ 384.313290] [<ffffffffa0043e70>] ? link_state_event+0x4e0/0x4e0 [tipc] [ 384.313290] [<ffffffff8105a954>] __do_softirq+0xf4/0x630 [ 384.313290] [<ffffffff8105afdd>] irq_exit+0x5d/0x60 [ 384.313290] [<ffffffff8103ade1>] smp_apic_timer_interrupt+0x41/0x50 [ 384.313290] [<ffffffff817144a0>] apic_timer_interrupt+0x70/0x80 [ 384.313290] <EOI> [<ffffffff8100db10>] ? default_idle+0x20/0x210 [ 384.313290] [<ffffffff8100db0e>] ? default_idle+0x1e/0x210 [ 384.313290] [<ffffffff8100e61a>] arch_cpu_idle+0xa/0x10 [ 384.313290] [<ffffffff81099803>] cpu_startup_entry+0x2c3/0x530 [ 384.313290] [<ffffffff810d2893>] ? clockevents_register_device+0x113/0x200 [ 384.313290] [<ffffffff81038b0f>] start_secondary+0x13f/0x170 Fixes: 8a0f6ebe8494 ("tipc: involve reference counter for node structure") Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-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/link.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/net/tipc/link.c b/net/tipc/link.c
index a6b30df6ec02..57be6e6aff99 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2143,7 +2143,6 @@ int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
err = __tipc_nl_add_node_links(net, &msg, node,
&prev_link);
tipc_node_unlock(node);
- tipc_node_put(node);
if (err)
goto out;