ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh

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>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 98fdcc6f51b1..e7fb7106550f 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -457,8 +457,10 @@ 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 ||