inet fragments: fix race between inet_frag_find and inet_frag_secret_rebuild
The problem is that while we work w/o the inet_frags.lock even
read-locked the secret rebuild timer may occur (on another CPU, since
BHs are still disabled in the inet_frag_find) and change the rnd seed
for ipv4/6 fragments.
It was caused by my patch fd9e63544cac30a34c951f0ec958038f0529e244
([INET]: Omit double hash calculations in xxx_frag_intern) late
in the 2.6.24 kernel, so this should probably be queued to -stable.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
index 798cabc..a60d7d1 100644
--- a/net/ipv6/reassembly.c
+++ b/net/ipv6/reassembly.c
@@ -247,6 +247,8 @@
arg.id = id;
arg.src = src;
arg.dst = dst;
+
+ read_lock(&ip6_frags.lock);
hash = ip6qhashfn(id, src, dst);
q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);