netdev - Re: [PATCH net 1/2] net: ipv6: fix dst refleaks in rpl, seg6 and ioam6 lwtunnels

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <738be35e-c891-48a2-9267-ca2dfd8fa650@uliege.be>
Date: Wed, 29 Jan 2025 17:10:25 +0100
From: Justin Iurman <justin.iurman@...ege.be>
To: Jakub Kicinski <kuba@...nel.org>, davem@...emloft.net
Cc: netdev@...r.kernel.org, edumazet@...gle.com, pabeni@...hat.com,
 andrew+netdev@...n.ch, horms@...nel.org, dsahern@...nel.org
Subject: Re: [PATCH net 1/2] net: ipv6: fix dst refleaks in rpl, seg6 and
 ioam6 lwtunnels

On 1/29/25 03:13, Jakub Kicinski wrote:
> dst_cache_get() gives us a reference, we need to release it.
> 
> Discovered by the ioam6.sh test, kmemleak was recently fixed
> to catch per-cpu memory leaks.
> 
> Fixes: 985ec6f5e623 ("net: ipv6: rpl_iptunnel: mitigate 2-realloc issue")
> Fixes: 40475b63761a ("net: ipv6: seg6_iptunnel: mitigate 2-realloc issue")
> Fixes: dce525185bc9 ("net: ipv6: ioam6_iptunnel: mitigate 2-realloc issue")
> Signed-off-by: Jakub Kicinski <kuba@...nel.org>
> ---
> CC: dsahern@...nel.org
> CC: justin.iurman@...ege.be
> ---
>   net/ipv6/ioam6_iptunnel.c | 5 +++--
>   net/ipv6/rpl_iptunnel.c   | 6 ++++--
>   net/ipv6/seg6_iptunnel.c  | 6 ++++--
>   3 files changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/net/ipv6/ioam6_iptunnel.c b/net/ipv6/ioam6_iptunnel.c
> index 28e5a89dc255..3936c137a572 100644
> --- a/net/ipv6/ioam6_iptunnel.c
> +++ b/net/ipv6/ioam6_iptunnel.c
> @@ -336,7 +336,7 @@ static int ioam6_do_encap(struct net *net, struct sk_buff *skb,
>   
>   static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
>   {
> -	struct dst_entry *dst = skb_dst(skb), *cache_dst;
> +	struct dst_entry *dst = skb_dst(skb), *cache_dst = NULL;
>   	struct in6_addr orig_daddr;
>   	struct ioam6_lwt *ilwt;
>   	int err = -EINVAL;
> @@ -407,7 +407,6 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
>   		cache_dst = ip6_route_output(net, NULL, &fl6);
>   		if (cache_dst->error) {
>   			err = cache_dst->error;
> -			dst_release(cache_dst);
>   			goto drop;
>   		}
>   
> @@ -426,8 +425,10 @@ static int ioam6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
>   		return dst_output(net, sk, skb);
>   	}
>   out:
> +	dst_release(cache_dst);
>   	return dst->lwtstate->orig_output(net, sk, skb);
>   drop:
> +	dst_release(cache_dst);
>   	kfree_skb(skb);
>   	return err;
>   }
> diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c
> index 7ba22d2f2bfe..9b7d03563115 100644
> --- a/net/ipv6/rpl_iptunnel.c
> +++ b/net/ipv6/rpl_iptunnel.c
> @@ -232,7 +232,6 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb)
>   		dst = ip6_route_output(net, NULL, &fl6);
>   		if (dst->error) {
>   			err = dst->error;
> -			dst_release(dst);
>   			goto drop;
>   		}
>   
> @@ -251,6 +250,7 @@ static int rpl_output(struct net *net, struct sock *sk, struct sk_buff *skb)
>   	return dst_output(net, sk, skb);
>   
>   drop:
> +	dst_release(dst);
>   	kfree_skb(skb);
>   	return err;
>   }
> @@ -269,8 +269,10 @@ static int rpl_input(struct sk_buff *skb)
>   	local_bh_enable();
>   
>   	err = rpl_do_srh(skb, rlwt, dst);
> -	if (unlikely(err))
> +	if (unlikely(err)) {
> +		dst_release(dst);
>   		goto drop;
> +	}
>   
>   	if (!dst) {
>   		ip6_route_input(skb);
> diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
> index 4bf937bfc263..eacc4e91b48e 100644
> --- a/net/ipv6/seg6_iptunnel.c
> +++ b/net/ipv6/seg6_iptunnel.c
> @@ -482,8 +482,10 @@ static int seg6_input_core(struct net *net, struct sock *sk,
>   	local_bh_enable();
>   
>   	err = seg6_do_srh(skb, dst);
> -	if (unlikely(err))
> +	if (unlikely(err)) {
> +		dst_release(dst);
>   		goto drop;
> +	}
>   
>   	if (!dst) {
>   		ip6_route_input(skb);
> @@ -571,7 +573,6 @@ static int seg6_output_core(struct net *net, struct sock *sk,
>   		dst = ip6_route_output(net, NULL, &fl6);
>   		if (dst->error) {
>   			err = dst->error;
> -			dst_release(dst);
>   			goto drop;
>   		}
>   
> @@ -593,6 +594,7 @@ static int seg6_output_core(struct net *net, struct sock *sk,
>   
>   	return dst_output(net, sk, skb);
>   drop:
> +	dst_release(dst);
>   	kfree_skb(skb);
>   	return err;
>   }

Reviewed-by: Justin Iurman <justin.iurman@...ege.be>

Thanks Jakub!