From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
commit 21985f43376cee092702d6cb963ff97a9d2ede68 upstream.
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.
Note we will rename inet6_destroy_sock() to inet6_cleanup_sock() and
remove unnecessary inet6_destroy_sock() calls in sk_prot->destroy()
in the future.
Fixes: 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/net/ipv6.h | 1 +
net/ipv6/af_inet6.c | 6 ++++++
net/ipv6/ipv6_sockglue.c | 20 ++++++++------------
3 files changed, 15 insertions(+), 12 deletions(-)
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -1118,6 +1118,7 @@ void ipv6_icmp_error(struct sock *sk, st
void ipv6_local_error(struct sock *sk, int err, struct flowi6 *fl6, u32 info);
void ipv6_local_rxpmtu(struct sock *sk, struct flowi6 *fl6, u32 mtu);
+void inet6_cleanup_sock(struct sock *sk);
int inet6_release(struct socket *sock);
int inet6_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len);
int inet6_getname(struct socket *sock, struct sockaddr *uaddr,
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -507,6 +507,12 @@ void inet6_destroy_sock(struct sock *sk)
}
EXPORT_SYMBOL_GPL(inet6_destroy_sock);
+void inet6_cleanup_sock(struct sock *sk)
+{
+ inet6_destroy_sock(sk);
+}
+EXPORT_SYMBOL_GPL(inet6_cleanup_sock);
+
/*
* This does both peername and sockname.
*/
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -429,9 +429,6 @@ static int do_ipv6_setsockopt(struct soc
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;
@@ -462,7 +459,6 @@ static int do_ipv6_setsockopt(struct soc
break;
}
- fl6_free_socklist(sk);
__ipv6_sock_mc_close(sk);
__ipv6_sock_ac_close(sk);
@@ -497,14 +493,14 @@ static int do_ipv6_setsockopt(struct soc
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);
+
+ /* Disable all options not to allocate memory anymore,
+ * but there is still a race. See the lockless path
+ * in udpv6_sendmsg() and ipv6_local_rxpmtu().
+ */
+ np->rxopt.all = 0;
+
+ inet6_cleanup_sock(sk);
/*
* ... and add it to the refcnt debug socks count
