From 903ce4abdf374e3365d93bcb3df56c62008835ba Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Tue, 5 Jul 2016 12:10:23 -0700 Subject: [PATCH] ipv6: Fix mem leak in rt6i_pcpu It was first reported and reproduced by Petr (thanks!) in https://bugzilla.kernel.org/show_bug.cgi?id=119581 free_percpu(rt->rt6i_pcpu) used to always happen in ip6_dst_destroy(). However, after fixing a deadlock bug in commit 9c7370a166b4 ("ipv6: Fix a potential deadlock when creating pcpu rt"), free_percpu() is not called before setting non_pcpu_rt->rt6i_pcpu to NULL. It is worth to note that rt6i_pcpu is protected by table->tb6_lock. kmemleak somehow did not report it. We nailed it down by observing the pcpu entries in /proc/vmallocinfo (first suggested by Hannes, thanks!). Signed-off-by: Martin KaFai Lau Fixes: 9c7370a166b4 ("ipv6: Fix a potential deadlock when creating pcpu rt") Reported-by: Petr Novopashenniy Tested-by: Petr Novopashenniy Acked-by: Hannes Frederic Sowa Cc: Hannes Frederic Sowa Cc: Petr Novopashenniy Signed-off-by: David S. Miller --- net/ipv6/ip6_fib.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 1bcef2369d64..771be1fa4176 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -177,6 +177,7 @@ static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt) } } + free_percpu(non_pcpu_rt->rt6i_pcpu); non_pcpu_rt->rt6i_pcpu = NULL; } -- 2.20.1