TIPCv2 registers its generic-netlink mutating commands without
permission flags. Generic netlink only checks CAP_NET_ADMIN when an
operation carries GENL_ADMIN_PERM or GENL_UNS_ADMIN_PERM, so callers
without CAP_NET_ADMIN can invoke these setters.

This allows an unprivileged caller to change TIPC control-plane state,
including bearer, link, network, monitor, peer and crypto-key state.
TIPC_NL_MEDIA_SET is broader because it updates the shared media
defaults returned by tipc_media_find(), including UDP MTU, priority,
tolerance and window values, which can affect later bearer setup.

Require CAP_NET_ADMIN for all TIPCv2 mutators. Use
GENL_UNS_ADMIN_PERM for network-namespace scoped state, matching the
legacy compat path and normal netns administration semantics. Use
GENL_ADMIN_PERM for TIPC_NL_MEDIA_SET because it mutates global media
defaults rather than state owned only by the target net namespace.

Fixes: 0655f6a8635b ("tipc: add bearer disable/enable to new netlink api")
Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Dominik 'Disconnect3d' Czarnota <dominik.czarnota@trailofbits.com>
---
 net/tipc/netlink.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 1a9a5bdaccf4..5bbe134284ac 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -152,11 +152,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_BEARER_DISABLE,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_bearer_disable,
 	},
 	{
 		.cmd	= TIPC_NL_BEARER_ENABLE,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_bearer_enable,
 	},
 	{
@@ -168,11 +170,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_BEARER_ADD,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_bearer_add,
 	},
 	{
 		.cmd	= TIPC_NL_BEARER_SET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_bearer_set,
 	},
 	{
@@ -197,11 +201,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_LINK_SET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_node_set_link,
 	},
 	{
 		.cmd	= TIPC_NL_LINK_RESET_STATS,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit   = tipc_nl_node_reset_link_stats,
 	},
 	{
@@ -213,6 +219,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_MEDIA_SET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_ADMIN_PERM,
 		.doit	= tipc_nl_media_set,
 	},
 	{
@@ -228,6 +235,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_NET_SET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_net_set,
 	},
 	{
@@ -238,6 +246,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_MON_SET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_node_set_monitor,
 	},
 	{
@@ -255,6 +264,7 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_PEER_REMOVE,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_peer_rm,
 	},
 #ifdef CONFIG_TIPC_MEDIA_UDP
@@ -269,11 +279,13 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 	{
 		.cmd	= TIPC_NL_KEY_SET,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_node_set_key,
 	},
 	{
 		.cmd	= TIPC_NL_KEY_FLUSH,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.flags	= GENL_UNS_ADMIN_PERM,
 		.doit	= tipc_nl_node_flush_key,
 	},
 #endif