ipv6: sr: fix possible use-after-free and null-ptr-deref

The pernet operations structure for the subsystem must be registered
before registering the generic netlink family.

Fixes: 915d7e5e5930 ("ipv6: sr: add code base for control plane support of SR-IPv6")
Signed-off-by: Vasiliy Kovalev <kovalev@altlinux.org>
Link: https://lore.kernel.org/r/20240215202717.29815-1-kovalev@altlinux.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index 29346a6..35508ab 100644 (file)
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -512,22 +512,24 @@ int __init seg6_init(void)
 {
        int err;
 
-       err = genl_register_family(&seg6_genl_family);
+       err = register_pernet_subsys(&ip6_segments_ops);
        if (err)
                goto out;
 
-       err = register_pernet_subsys(&ip6_segments_ops);
+       err = genl_register_family(&seg6_genl_family);
        if (err)
-               goto out_unregister_genl;
+               goto out_unregister_pernet;
 
 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
        err = seg6_iptunnel_init();
        if (err)
-               goto out_unregister_pernet;
+               goto out_unregister_genl;
 
        err = seg6_local_init();
-       if (err)
-               goto out_unregister_pernet;
+       if (err) {
+               seg6_iptunnel_exit();
+               goto out_unregister_genl;
+       }
 #endif
 
 #ifdef CONFIG_IPV6_SEG6_HMAC
@@ -548,11 +550,11 @@ out_unregister_iptun:
 #endif
 #endif
 #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
-out_unregister_pernet:
-       unregister_pernet_subsys(&ip6_segments_ops);
-#endif
 out_unregister_genl:
        genl_unregister_family(&seg6_genl_family);
+#endif
+out_unregister_pernet:
+       unregister_pernet_subsys(&ip6_segments_ops);
        goto out;
 }