4.4-stable review patch. If anyone has any objections, please let me know.
------------------ From: Martin KaFai Lau <ka...@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 <ka...@fb.com> Fixes: 9c7370a166b4 ("ipv6: Fix a potential deadlock when creating pcpu rt") Reported-by: Petr Novopashenniy <p...@rusnet.ru> Tested-by: Petr Novopashenniy <p...@rusnet.ru> Acked-by: Hannes Frederic Sowa <han...@stressinduktion.org> Cc: Hannes Frederic Sowa <han...@stressinduktion.org> Cc: Petr Novopashenniy <p...@rusnet.ru> Signed-off-by: David S. Miller <da...@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gre...@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 @@ -179,6 +179,7 @@ static void rt6_free_pcpu(struct rt6_inf } } + free_percpu(non_pcpu_rt->rt6i_pcpu); non_pcpu_rt->rt6i_pcpu = NULL; }
