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

[Hangbin Liu <liuhangbin@gmail.com>]

On Tue, May 07, 2024 at 11:14:45AM +0200, Sabrina Dubroca wrote:
> 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.

Ah, yes, I will add the CONFIG_IPV6_SEG6_LWTUNNEL definition in v2.

diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c
index 3c5ccc52d0e1..6a80d93399ce 100644
--- a/net/ipv6/seg6.c
+++ b/net/ipv6/seg6.c
@@ -549,7 +549,9 @@ int __init seg6_init(void)
        seg6_iptunnel_exit();
 #endif
 #endif
+#ifdef CONFIG_IPV6_SEG6_LWTUNNEL
 out_unregister_genl:
+#endif
        genl_unregister_family(&seg6_genl_family);
 out_unregister_pernet:
        unregister_pernet_subsys(&ip6_segments_ops);

Thanks
Hangbin