lkml.org 
[lkml]   [2022]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v2 net 2/5] udp: Call inet6_destroy_sock() in setsockopt(IPV6_ADDRFORM).
On Tue, Sep 27, 2022 at 5:28 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote:
>
> Commit 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") forgot
> to add a change to free inet6_sk(sk)->rxpmtu while converting an IPv6
> socket into IPv4 with IPV6_ADDRFORM. After conversion, sk_prot is
> changed to udp_prot and ->destroy() never cleans it up, resulting in
> a memory leak.
>
> This is due to the discrepancy between inet6_destroy_sock() and
> IPV6_ADDRFORM, so let's call inet6_destroy_sock() from IPV6_ADDRFORM
> to remove the difference.
>
> However, this is not enough for now because rxpmtu can be changed
> without lock_sock() after commit 03485f2adcde ("udpv6: Add lockless
> sendmsg() support"). We will fix this case in the following patch.
>
> Fixes: 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support")
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> ---
> net/ipv6/ipv6_sockglue.c | 15 +++------------
> 1 file changed, 3 insertions(+), 12 deletions(-)
>
> diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
> index b61066ac8648..030a4cf23ceb 100644
> --- a/net/ipv6/ipv6_sockglue.c
> +++ b/net/ipv6/ipv6_sockglue.c
> @@ -431,9 +431,6 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
> if (optlen < sizeof(int))
> goto e_inval;
> if (val == PF_INET) {
> - struct ipv6_txoptions *opt;
> - struct sk_buff *pktopt;
> -
> if (sk->sk_type == SOCK_RAW)
> break;
>
> @@ -464,7 +461,6 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
> break;
> }
>
> - fl6_free_socklist(sk);
> __ipv6_sock_mc_close(sk);
> __ipv6_sock_ac_close(sk);
>
> @@ -501,14 +497,9 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
> sk->sk_socket->ops = &inet_dgram_ops;
> sk->sk_family = PF_INET;
> }
> - opt = xchg((__force struct ipv6_txoptions **)&np->opt,
> - NULL);
> - if (opt) {
> - atomic_sub(opt->tot_len, &sk->sk_omem_alloc);
> - txopt_put(opt);
> - }
> - pktopt = xchg(&np->pktoptions, NULL);
> - kfree_skb(pktopt);
> +

Why is this needed ? I think a comment could help.
> + np->rxopt.all = 0;

> + inet6_destroy_sock(sk);

This name is unfortunate. This really is an inet6_cleanup_sock() in
this context.

>
> /*
> * ... and add it to the refcnt debug socks count
> --
> 2.30.2
>

\
 
 \ /
  Last update: 2022-09-28 07:06    [W:0.150 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site