diff options
| author | Maoyi Xie <maoyixie.tju@gmail.com> | 2026-06-12 16:59:39 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-17 16:01:52 -0700 |
| commit | f00a50876d2818bd6dc86fa98b3ef360884c53c8 (patch) | |
| tree | 4834332b245daecdfbf613e0d7220ee1e3dc962c | |
| parent | 2496fa0b7d180b3ad356b514e7ff93bb14e6140a (diff) | |
net: ip6_gre: require CAP_NET_ADMIN in the device netns for changelink
ip6gre_changelink() and ip6erspan_changelink() operate on at most two
netns, dev_net(dev) and the tunnel link netns t->net. They differ once
the device is created in or moved to a netns other than the one the
request runs in. The rtnl changelink path checks CAP_NET_ADMIN only
against dev_net(dev), so a caller privileged there but not in t->net can
rewrite a tunnel that lives in t->net.
Gate both ops on rtnl_dev_link_net_capable() at their top, before any
attribute is parsed.
Reported-by: Xiao Liang <shaw.leon@gmail.com>
Closes: https://lore.kernel.org/netdev/CABAhCOSzP1vaThGV35_VnsRCb=87_CPjPVsTHbq905k8A+BuUg@mail.gmail.com/
Fixes: 690afc165bb3 ("net: ip6_gre: fix moving ip6gre between namespaces")
Cc: stable@vger.kernel.org
Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260612085941.3158249-6-maoyixie.tju@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv6/ip6_gre.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 795be59946f7..7c09a269b352 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -2047,6 +2047,9 @@ static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[], struct ip6gre_net *ign = net_generic(t->net, ip6gre_net_id); struct __ip6_tnl_parm p; + if (!rtnl_dev_link_net_capable(dev, t->net)) + return -EPERM; + t = ip6gre_changelink_common(dev, tb, data, &p, extack); if (IS_ERR(t)) return PTR_ERR(t); @@ -2266,6 +2269,9 @@ static int ip6erspan_changelink(struct net_device *dev, struct nlattr *tb[], struct __ip6_tnl_parm p; struct ip6gre_net *ign; + if (!rtnl_dev_link_net_capable(dev, t->net)) + return -EPERM; + ign = net_generic(t->net, ip6gre_net_id); t = ip6gre_changelink_common(dev, tb, data, &p, extack); if (IS_ERR(t)) |