kernel: act_ctinfo: backport memory leak fix

[ Upstream commit 09d4f10a5e78d76a53e3e584f1e6a701b6d24108 ]

Implement a cleanup method to properly free ci->params

BUG: memory leak
unreferenced object 0xffff88811746e2c0 (size 64):
 comm "syz-executor617", pid 7106, jiffies 4294943055 (age 14.250s)
 hex dump (first 32 bytes):
   00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
   c0 34 60 84 ff ff ff ff 00 00 00 00 00 00 00 00  .4`.............
 backtrace:
   [<0000000015aa236f>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
   [<0000000015aa236f>] slab_post_alloc_hook mm/slab.h:586 [inline]
   [<0000000015aa236f>] slab_alloc mm/slab.c:3320 [inline]
   [<0000000015aa236f>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3549
   [<000000002c946bd1>] kmalloc include/linux/slab.h:556 [inline]
   [<000000002c946bd1>] kzalloc include/linux/slab.h:670 [inline]
   [<000000002c946bd1>] tcf_ctinfo_init+0x21a/0x530 net/sched/act_ctinfo.c:236
   [<0000000086952cca>] tcf_action_init_1+0x400/0x5b0 net/sched/act_api.c:944
   [<000000005ab29bf8>] tcf_action_init+0x135/0x1c0 net/sched/act_api.c:1000
   [<00000000392f56f9>] tcf_action_add+0x9a/0x200 net/sched/act_api.c:1410
   [<0000000088f3c5dd>] tc_ctl_action+0x14d/0x1bb net/sched/act_api.c:1465
   [<000000006b39d986>] rtnetlink_rcv_msg+0x178/0x4b0 net/core/rtnetlink.c:5424
   [<00000000fd6ecace>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477
   [<0000000047493d02>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5442
   [<00000000bdcf8286>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
   [<00000000bdcf8286>] netlink_unicast+0x223/0x310 net/netlink/af_netlink.c:1328
   [<00000000fc5b92d9>] netlink_sendmsg+0x2c0/0x570 net/netlink/af_netlink.c:1917
   [<00000000da84d076>] sock_sendmsg_nosec net/socket.c:639 [inline]
   [<00000000da84d076>] sock_sendmsg+0x54/0x70 net/socket.c:659
   [<0000000042fb2eee>] ____sys_sendmsg+0x2d0/0x300 net/socket.c:2330
   [<000000008f23f67e>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2384
   [<00000000d838e4f6>] __sys_sendmsg+0x80/0xf0 net/socket.c:2417
   [<00000000289a9cb1>] __do_sys_sendmsg net/socket.c:2426 [inline]
   [<00000000289a9cb1>] __se_sys_sendmsg net/socket.c:2424 [inline]
   [<00000000289a9cb1>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2424

Fixes: 24ec483cec98 ("net: sched: Introduce act_ctinfo action")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

1 files changed, 15 insertions, 4 deletions

diff --git a/target/linux/generic/backport-4.19/380-v5.3-net-sched-Introduce-act_ctinfo-action.patch b/target/linux/generic/backport-4.19/380-v5.3-net-sched-Introduce-act_ctinfo-action.patch
index 8e04dce309..a680402f26 100644
--- a/target/linux/generic/backport-4.19/380-v5.3-net-sched-Introduce-act_ctinfo-action.patch
+++ b/target/linux/generic/backport-4.19/380-v5.3-net-sched-Introduce-act_ctinfo-action.patch
@@ -1,4 +1,4 @@
-From 6d8071bbbdcd9d3a2fbb49e55b51617906e3b816 Mon Sep 17 00:00:00 2001
+From d129a72f465dab2d9fc8f1580c38600a8b808327 Mon Sep 17 00:00:00 2001
 From: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
 Date: Wed, 13 Mar 2019 20:54:49 +0000
 Subject: [PATCH] net: sched: Backport Introduce act_ctinfo action
@@ -112,9 +112,9 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
  include/uapi/linux/tc_act/tc_ctinfo.h     |  29 ++
  net/sched/Kconfig                         |  17 +
  net/sched/Makefile                        |   1 +
- net/sched/act_ctinfo.c                    | 409 ++++++++++++++++++++++
+ net/sched/act_ctinfo.c                    | 420 ++++++++++++++++++++++
  tools/testing/selftests/tc-testing/config |   1 +
- 7 files changed, 492 insertions(+), 1 deletion(-)
+ 7 files changed, 503 insertions(+), 1 deletion(-)
  create mode 100644 include/net/tc_act/tc_ctinfo.h
  create mode 100644 include/uapi/linux/tc_act/tc_ctinfo.h
  create mode 100644 net/sched/act_ctinfo.c
@@ -237,7 +237,7 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
  obj-$(CONFIG_NET_IFE_SKBMARK)	+= act_meta_mark.o
 --- /dev/null
 +++ b/net/sched/act_ctinfo.c
-@@ -0,0 +1,409 @@
+@@ -0,0 +1,420 @@
 +// SPDX-License-Identifier: GPL-2.0+
 +/* net/sched/act_ctinfo.c  netfilter ctinfo connmark actions
 + *
@@ -601,6 +601,16 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
 +	return tcf_idr_search(tn, a, index);
 +}
 +
++static void tcf_ctinfo_cleanup(struct tc_action *a)
++{
++	struct tcf_ctinfo *ci = to_ctinfo(a);
++	struct tcf_ctinfo_params *cp;
++
++	cp = rcu_dereference_protected(ci->params, 1);
++	if (cp)
++		kfree_rcu(cp, rcu);
++}
++
 +static struct tc_action_ops act_ctinfo_ops = {
 +	.kind	= "ctinfo",
 +	.type	= TCA_ID_CTINFO,
@@ -609,6 +619,7 @@ Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
 +	.dump	= tcf_ctinfo_dump,
 +	.init	= tcf_ctinfo_init,
 +	.walk	= tcf_ctinfo_walker,
++	.cleanup= tcf_ctinfo_cleanup,
 +	.lookup	= tcf_ctinfo_search,
 +	.size	= sizeof(struct tcf_ctinfo),
 +};