ipv6: protect flow label renew against GC
Take ip6_fl_lock before to read and update
a label.
v2: protect only the relevant code
Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index 5f10b0d..98fdcc6 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -345,6 +345,8 @@
expires = check_linger(expires);
if (!expires)
return -EPERM;
+
+ spin_lock_bh(&ip6_fl_lock);
fl->lastuse = jiffies;
if (time_before(fl->linger, linger))
fl->linger = linger;
@@ -352,6 +354,8 @@
expires = fl->linger;
if (time_before(fl->expires, fl->lastuse + expires))
fl->expires = fl->lastuse + expires;
+ spin_unlock_bh(&ip6_fl_lock);
+
return 0;
}
