memory leak in ctnetlink

memory leak in ctnetlink_start
Status: upstream: reported C repro on 2020/06/09 21:58
Reported-by: syzbot+b005af2cfb0411e617de@syzkaller.appspotmail.com
First crash: 376d, last: 372d

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2021/04/11 11:35	15m	phil@philpotter.co.uk		upstream	OK

Sample crash report:

executing program
BUG: memory leak
unreferenced object 0xffff88811e56f800 (size 128):
  comm "syz-executor221", pid 6470, jiffies 4294943125 (age 24.460s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<0000000021b8300e>] kmalloc include/linux/slab.h:555 [inline]
    [<0000000021b8300e>] kzalloc include/linux/slab.h:669 [inline]
    [<0000000021b8300e>] ctnetlink_alloc_filter+0x3a/0x2a0 net/netfilter/nf_conntrack_netlink.c:924
    [<00000000adb3ab64>] ctnetlink_start+0x3a/0x80 net/netfilter/nf_conntrack_netlink.c:998
    [<00000000538523d4>] __netlink_dump_start+0x1a3/0x2e0 net/netlink/af_netlink.c:2343
    [<0000000052988833>] netlink_dump_start include/linux/netlink.h:246 [inline]
    [<0000000052988833>] ctnetlink_get_conntrack+0x26d/0x2f0 net/netfilter/nf_conntrack_netlink.c:1611
    [<000000007d4d8e5c>] nfnetlink_rcv_msg+0x32f/0x370 net/netfilter/nfnetlink.c:229
    [<00000000df1d34fb>] netlink_rcv_skb+0x5a/0x180 net/netlink/af_netlink.c:2469
    [<0000000014d0ae77>] nfnetlink_rcv+0x83/0x1b0 net/netfilter/nfnetlink.c:563
    [<00000000edfb144b>] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
    [<00000000edfb144b>] netlink_unicast+0x20a/0x2f0 net/netlink/af_netlink.c:1329
    [<0000000024f1e510>] netlink_sendmsg+0x2b5/0x560 net/netlink/af_netlink.c:1918
    [<000000005467a641>] sock_sendmsg_nosec net/socket.c:652 [inline]
    [<000000005467a641>] sock_sendmsg+0x4c/0x60 net/socket.c:672
    [<000000001432f3c2>] ____sys_sendmsg+0x2c4/0x2f0 net/socket.c:2352
    [<000000004a43a4ab>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2406
    [<000000003f0f4f52>] __sys_sendmsg+0x77/0xe0 net/socket.c:2439
    [<0000000057090328>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
    [<00000000d55eddd7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Crashes (4):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-gce-leak	2020/06/12 09:05	upstream	7ae77150	58802067	.config	log	report	syz	C
ci-upstream-gce-leak	2020/06/11 03:18	upstream	7ae77150	a6f7998d	.config	log	report	syz	C
ci-upstream-gce-leak	2020/06/10 09:28	upstream	7ae77150	860c4de9	.config	log	report	syz	C
ci-upstream-gce-leak	2020/06/08 07:25	upstream	7ae77150	7751efd0	.config	log	report	syz	C