Re: [PATCH net] ipv6: sr: fix invalid unregister error path

[Sabrina Dubroca <sd@queasysnail.net>]

2024-05-07, 16:11:00 +0800, Hangbin Liu wrote:
> The error path of seg6_init() is wrong in case CONFIG_IPV6_SEG6_LWTUNNEL
> is not defined. In that case if seg6_hmac_init() fails, the
> genl_unregister_family() isn't called.
> 
> At the same time, add seg6_local_exit() and fix the genl unregister order
> in seg6_exit().
> 
> Fixes: 5559cea2d5aa ("ipv6: sr: fix possible use-after-free and null-ptr-deref")
> Reported-by: Guillaume Nault <gnault@redhat.com>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  net/ipv6/seg6.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
> index 35508abd76f4..3c5ccc52d0e1 100644
> --- a/net/ipv6/seg6.c
> +++ b/net/ipv6/seg6.c
> @@ -549,10 +549,8 @@ int __init seg6_init(void)
>  	seg6_iptunnel_exit();
>  #endif
>  #endif
> -#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
>  out_unregister_genl:
>  	genl_unregister_family(&seg6_genl_family);

That label will be defined but unused for !CONFIG_IPV6_SEG6_LWTUNNEL.

> -#endif
>  out_unregister_pernet:
>  	unregister_pernet_subsys(&ip6_segments_ops);
>  	goto out;
> @@ -564,8 +562,9 @@ void seg6_exit(void)
>  	seg6_hmac_exit();
>  #endif
>  #ifdef CONFIG_IPV6_SEG6_LWTUNNEL
> +	seg6_local_exit();
>  	seg6_iptunnel_exit();
>  #endif
> -	unregister_pernet_subsys(&ip6_segments_ops);
>  	genl_unregister_family(&seg6_genl_family);
> +	unregister_pernet_subsys(&ip6_segments_ops);
>  }
> -- 
> 2.43.0
> 
> 

-- 
Sabrina