Messages in this thread | | | From | Eric Dumazet <> | Date | Tue, 27 Sep 2022 22:05:09 -0700 | Subject | Re: [PATCH v2 net 2/5] udp: Call inet6_destroy_sock() in setsockopt(IPV6_ADDRFORM). |
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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 >
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