kernel/linux.git/net/mpls, branch v6.19.11

mpls: add missing unregister_netdevice_notifier to mpls_init

2026-03-25T10:13:25+00:00

[ Upstream commit 99600f79b28c83c68bae199a3d8e95049a758308 ] If mpls_init() fails after registering mpls_dev_notifier, it never gets removed. Add the missing unregister_netdevice_notifier() call to the error handling path. Fixes: 5be2062e3080 ("mpls: Handle error of rtnl_register_module().") Signed-off-by: Sabrina Dubroca Link: https://patch.msgid.link/7c55363c4f743d19e2306204a134407c90a69bbb.1773228081.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

mpls: Drop RTNL for RTM_NEWROUTE, RTM_DELROUTE, and RTM_GETROUTE.

2025-11-04T01:40:54+00:00

RTM_NEWROUTE looks up dev under RCU (ip_route_output(), ipv6_stub->ipv6_dst_lookup_flow(), netdev_get_by_index()), and each neighbour holds the refcnt of its dev. Also, net->mpls.platform_label is protected by a dedicated per-netns mutex. Now, no MPLS code depends on RTNL. Let's drop RTNL for RTM_NEWROUTE, RTM_DELROUTE, and RTM_GETROUTE. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-14-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Protect net->mpls.platform_label with a per-netns mutex.

2025-11-04T01:40:53+00:00

MPLS (re)uses RTNL to protect net->mpls.platform_label, but the lock does not need to be RTNL at all. Let's protect net->mpls.platform_label with a dedicated per-netns mutex. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-13-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Convert RTM_GETNETCONF to RCU.

2025-11-04T01:40:52+00:00

mpls_netconf_get_devconf() calls __dev_get_by_index(), and this only depends on RTNL. Let's convert mpls_netconf_get_devconf() to RCU and use dev_get_by_index_rcu(). Note that nlmsg_new() is moved ahead to use GFP_KERNEL. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-12-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Convert mpls_dump_routes() to RCU.

2025-11-04T01:40:51+00:00

mpls_dump_routes() sets fib_dump_filter.rtnl_held to true and calls __dev_get_by_index() in mpls_valid_fib_dump_req(). This is the only RTNL dependant in mpls_dump_routes(). Also, synchronize_rcu() in resize_platform_label_table() guarantees that net->mpls.platform_label is alive under RCU. Let's convert mpls_dump_routes() to RCU and use dev_get_by_index_rcu(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-11-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Use mpls_route_input() where appropriate.

2025-11-04T01:40:50+00:00

In many places, we uses rtnl_dereference() twice for net->mpls.platform_label and net->mpls.platform_label[index]. Let's replace the code with mpls_route_input(). We do not use mpls_route_input() in mpls_dump_routes() since we will rely on RCU there. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-10-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Add mpls_route_input().

2025-11-04T01:40:49+00:00

mpls_route_input_rcu() is called from mpls_forward() and mpls_getroute(). The former is under RCU, and the latter is under RTNL, so mpls_route_input_rcu() uses rcu_dereference_rtnl(). Let's use rcu_dereference() in mpls_route_input_rcu() and add an RTNL variant for mpls_getroute(). Later, we will remove rtnl_dereference() there. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-9-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Pass net to mpls_dev_get().

2025-11-04T01:40:48+00:00

We will replace RTNL with a per-netns mutex to protect dev->mpls_ptr. Then, we will use rcu_dereference_protected() with the lockdep_is_held() annotation, which requires net to access the per-netns mutex. However, dev_net(dev) is not safe without RTNL. Let's pass net to mpls_dev_get(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-8-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Add mpls_dev_rcu().

2025-11-04T01:40:48+00:00

mpls_dev_get() uses rcu_dereference_rtnl() to fetch dev->mpls_ptr. We will replace RTNL with a dedicated mutex to protect the field. Then, we will use rcu_dereference_protected() for clarity. Let's add mpls_dev_rcu() for the RCU reader. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-7-kuniyu@google.com Signed-off-by: Jakub Kicinski

mpls: Use in6_dev_rcu() and dev_net_rcu() in mpls_forward() and mpls_xmit().

2025-11-04T01:40:47+00:00

mpls_forward() and mpls_xmit() are called under RCU. Let's use in6_dev_rcu() and dev_net_rcu() there to annotate as such. Now we pass net to mpls_stats_inc_outucastpkts() not to read dev_net_rcu() twice. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20251029173344.2934622-6-kuniyu@google.com Signed-off-by: Jakub Kicinski