4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Olivier Matz <olivier.matz@xxxxxxxxx>
[ Upstream commit ab5098fa25b91cb6fe0a0676f17abb64f2bbf024 ]
In changelink ops, the ip6gre_net pointer is retrieved from
dev_net(dev), which is wrong in case of x-netns. Thus, the tunnel is not
unlinked from its current list and is relinked into another net
namespace. This corrupts the tunnel lists and can later trigger a kernel
oops.
Fix this by retrieving the netns from device private area.
Fixes: c8632fc30bb0 ("net: ip6_gre: Split up ip6gre_changelink()")
Cc: Petr Machata <petrm@xxxxxxxxxxxx>
Signed-off-by: Olivier Matz <olivier.matz@xxxxxxxxx>
Acked-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/ip6_gre.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -2029,9 +2029,9 @@ static int ip6gre_changelink(struct net_
struct nlattr *data[],
struct netlink_ext_ack *extack)
{
- struct ip6gre_net *ign = net_generic(dev_net(dev), ip6gre_net_id);
+ struct ip6_tnl *t = netdev_priv(dev);
+ struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id);
struct __ip6_tnl_parm p;
- struct ip6_tnl *t;
t = ip6gre_changelink_common(dev, tb, data, &p, extack);
if (IS_ERR(t))
