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authorPavel Emelyanov <xemul@parallels.com>2010-10-27 05:43:53 +0000
committerDavid S. Miller <davem@davemloft.net>2010-10-27 14:20:08 -0700
commit74b0b85b88aaa952023762e0280799aaae849841 (patch)
treea3049c0efd6332785e2323581506c89d49c67538 /net/ipv4/ip_gre.c
parent1933f0c09438ed8ccfee2281b814d9b26cef336c (diff)
downloadlinux-2.6.38-lt-ux500-74b0b85b88aaa952023762e0280799aaae849841.tar.gz
tunnels: Fix tunnels change rcu protection
After making rcu protection for tunnels (ipip, gre, sit and ip6) a bug was introduced into the SIOCCHGTUNNEL code. The tunnel is first unlinked, then addresses change, then it is linked back probably into another bucket. But while changing the parms, the hash table is unlocked to readers and they can lookup the improper tunnel. Respective commits are b7285b79 (ipip: get rid of ipip_lock), 1507850b (gre: get rid of ipgre_lock), 3a43be3c (sit: get rid of ipip6_lock) and 94767632 (ip6tnl: get rid of ip6_tnl_lock). The quick fix is to wait for quiescent state to pass after unlinking, but if it is inappropriate I can invent something better, just let me know. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_gre.c')
-rw-r--r--net/ipv4/ip_gre.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index d0ffcbe369b..01087e035b7 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1072,6 +1072,7 @@ ipgre_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
break;
}
ipgre_tunnel_unlink(ign, t);
+ synchronize_net();
t->parms.iph.saddr = p.iph.saddr;
t->parms.iph.daddr = p.iph.daddr;
t->parms.i_key = p.i_key;