Patch "tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct()." has been added to the 4.14-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tcp-udp-call-inet6_destroy_sock-in-ipv6-sk-sk_destruct.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From d38afeec26ed4739c640bf286c270559aab2ba5f Mon Sep 17 00:00:00 2001
From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Thu, 6 Oct 2022 11:53:47 -0700
Subject: tcp/udp: Call inet6_destroy_sock() in IPv6 sk->sk_destruct().

From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>

commit d38afeec26ed4739c640bf286c270559aab2ba5f upstream.

Originally, inet6_sk(sk)->XXX were changed under lock_sock(), so we were
able to clean them up by calling inet6_destroy_sock() during the IPv6 ->
IPv4 conversion by IPV6_ADDRFORM.  However, commit 03485f2adcde ("udpv6:
Add lockless sendmsg() support") added a lockless memory allocation path,
which could cause a memory leak:

setsockopt(IPV6_ADDRFORM)                 sendmsg()
+-----------------------+                 +-------+
- do_ipv6_setsockopt(sk, ...)             - udpv6_sendmsg(sk, ...)
  - sockopt_lock_sock(sk)                   ^._ called via udpv6_prot
    - lock_sock(sk)                             before WRITE_ONCE()
  - WRITE_ONCE(sk->sk_prot, &tcp_prot)
  - inet6_destroy_sock()                    - if (!corkreq)
  - sockopt_release_sock(sk)                  - ip6_make_skb(sk, ...)
    - release_sock(sk)                          ^._ lockless fast path for
                                                    the non-corking case

                                                - __ip6_append_data(sk, ...)
                                                  - ipv6_local_rxpmtu(sk, ...)
                                                    - xchg(&np->rxpmtu, skb)
                                                      ^._ rxpmtu is never freed.

                                                - goto out_no_dst;

                                            - lock_sock(sk)

For now, rxpmtu is only the case, but not to miss the future change
and a similar bug fixed in commit e27326009a3d ("net: ping6: Fix
memleak in ipv6_renew_options()."), let's set a new function to IPv6
sk->sk_destruct() and call inet6_cleanup_sock() there.  Since the
conversion does not change sk->sk_destruct(), we can guarantee that
we can clean up IPv6 resources finally.

We can now remove all inet6_destroy_sock() calls from IPv6 protocol
specific ->destroy() functions, but such changes are invasive to
backport.  So they can be posted as a follow-up later for net-next.

Fixes: 03485f2adcde ("udpv6: Add lockless sendmsg() 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>
---
 net/dccp/dccp.h     |    1 +
 net/dccp/ipv6.c     |   15 ++++++++-------
 net/dccp/proto.c    |    8 +++++++-
 net/ipv6/af_inet6.c |    1 +
 4 files changed, 17 insertions(+), 8 deletions(-)

--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -291,6 +291,7 @@ int dccp_rcv_state_process(struct sock *
 int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
 			 const struct dccp_hdr *dh, const unsigned int len);
 
+void dccp_destruct_common(struct sock *sk);
 int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized);
 void dccp_destroy_sock(struct sock *sk);
 
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -1000,6 +1000,12 @@ static const struct inet_connection_sock
 #endif
 };
 
+static void dccp_v6_sk_destruct(struct sock *sk)
+{
+	dccp_destruct_common(sk);
+	inet6_sock_destruct(sk);
+}
+
 /* NOTE: A lot of things set to zero explicitly by call to
  *       sk_alloc() so need not be done here.
  */
@@ -1012,17 +1018,12 @@ static int dccp_v6_init_sock(struct sock
 		if (unlikely(!dccp_v6_ctl_sock_initialized))
 			dccp_v6_ctl_sock_initialized = 1;
 		inet_csk(sk)->icsk_af_ops = &dccp_ipv6_af_ops;
+		sk->sk_destruct = dccp_v6_sk_destruct;
 	}
 
 	return err;
 }
 
-static void dccp_v6_destroy_sock(struct sock *sk)
-{
-	dccp_destroy_sock(sk);
-	inet6_destroy_sock(sk);
-}
-
 static struct timewait_sock_ops dccp6_timewait_sock_ops = {
 	.twsk_obj_size	= sizeof(struct dccp6_timewait_sock),
 };
@@ -1045,7 +1046,7 @@ static struct proto dccp_v6_prot = {
 	.accept		   = inet_csk_accept,
 	.get_port	   = inet_csk_get_port,
 	.shutdown	   = dccp_shutdown,
-	.destroy	   = dccp_v6_destroy_sock,
+	.destroy	   = dccp_destroy_sock,
 	.orphan_count	   = &dccp_orphan_count,
 	.max_header	   = MAX_DCCP_HEADER,
 	.obj_size	   = sizeof(struct dccp6_sock),
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -171,12 +171,18 @@ const char *dccp_packet_name(const int t
 
 EXPORT_SYMBOL_GPL(dccp_packet_name);
 
-static void dccp_sk_destruct(struct sock *sk)
+void dccp_destruct_common(struct sock *sk)
 {
 	struct dccp_sock *dp = dccp_sk(sk);
 
 	ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk);
 	dp->dccps_hc_tx_ccid = NULL;
+}
+EXPORT_SYMBOL_GPL(dccp_destruct_common);
+
+static void dccp_sk_destruct(struct sock *sk)
+{
+	dccp_destruct_common(sk);
 	inet_sock_destruct(sk);
 }
 
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -106,6 +106,7 @@ static __inline__ struct ipv6_pinfo *ine
 
 	return (struct ipv6_pinfo *)(((u8 *)sk) + offset);
 }
+EXPORT_SYMBOL_GPL(inet6_sock_destruct);
 
 static int inet6_create(struct net *net, struct socket *sock, int protocol,
 			int kern)


Patches currently in stable-queue which might be from kuniyu@xxxxxxxxxx are

queue-4.14/tcp-udp-call-inet6_destroy_sock-in-ipv6-sk-sk_destruct.patch
queue-4.14/udp-call-inet6_destroy_sock-in-setsockopt-ipv6_addrform.patch



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux