ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh

[ Upstream commit f8c31c8f80dd882f7eb49276989a4078d33d67a7 ]

Fixes a suspicious rcu derference warning.

Cc: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 46e88433ec7d229550eecadc29f8eacc139fe5b2..f0ccdb787100c56acb3f4e38e57a434f7ffc2b5c 100644 (file)
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -453,8 +453,10 @@ static int mem_check(struct sock *sk)
        if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
                return 0;
 
+       rcu_read_lock_bh();
        for_each_sk_fl_rcu(np, sfl)
                count++;
+       rcu_read_unlock_bh();
 
        if (room <= 0 ||
            ((count >= FL_MAX_PER_SOCK ||