On Wed, 6 Feb 2019 20:51:11 +0800
Hangbin Liu <liuhang...@gmail.com> wrote:
> If we disabled IPv6 from kernel boot up cmd(ipv6.disable=1), we should not
> call ip6_err_gen_icmpv6_unreach().
>
> Reproducer:
> ip link add sit1 type sit local 10.10.0.1 remote 10.10.1.1 ttl 1
> ip link set sit1 up
> ip addr add 192.168.0.1/24 dev sit1
> ping 192.168.0.2
>
> Reported-by: Jianlin Shi <ji...@redhat.com>
> Signed-off-by: Hangbin Liu <liuhang...@gmail.com>
> ---
> net/ipv6/sit.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
> index 1e03305c0549..e43fbac0fd1a 100644
> --- a/net/ipv6/sit.c
> +++ b/net/ipv6/sit.c
> @@ -493,6 +493,7 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
> const int type = icmp_hdr(skb)->type;
> const int code = icmp_hdr(skb)->code;
> unsigned int data_len = 0;
> + struct inet6_dev *idev;
> struct ip_tunnel *t;
> int sifindex;
> int err;
> @@ -546,8 +547,13 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
> }
>
> err = 0;
> - if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
> +
> + idev = in6_dev_get(skb->dev);
> + if (idev &&
> + !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len)) {
> + in6_dev_put(idev);
> goto out;
> + }
You are leaking a reference if idev && ip6_err_gen_icmpv6_unreach(...).
You should call in6_dev_put(idev) whenever idev is not NULL instead.
--
Stefano
