| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.6 075/203] ipv6: Fix mem leak in rt6i_pcpu | Date | Mon, 25 Jul 2016 13:54:50 -0700 |
| |
4.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin KaFai Lau <kafai@fb.com>
[ Upstream commit 903ce4abdf374e3365d93bcb3df56c62008835ba ]
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 <kafai@fb.com> Fixes: 9c7370a166b4 ("ipv6: Fix a potential deadlock when creating pcpu rt") Reported-by: Petr Novopashenniy <pety@rusnet.ru> Tested-by: Petr Novopashenniy <pety@rusnet.ru> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Petr Novopashenniy <pety@rusnet.ru> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv6/ip6_fib.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -177,6 +177,7 @@ static void rt6_free_pcpu(struct rt6_inf } } + free_percpu(non_pcpu_rt->rt6i_pcpu); non_pcpu_rt->rt6i_pcpu = NULL; }
|