memory leak in nf_tables_addchain

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    449dc8c9 Merge tag 'for-v5.9' of git://git.kernel.org/pub/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14f87006900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4810fa4a53b3aa2c
dashboard link: https://syzkaller.appspot.com/bug?extid=c99868fde67014f7e9f5
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17fbf6e6900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12781652900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c99868fde67014f7e9f5@xxxxxxxxxxxxxxxxxxxxxxxxx

executing program
BUG: memory leak
unreferenced object 0xffff888119189f80 (size 128):
  comm "syz-executor071", pid 6469, jiffies 4294944001 (age 12.440s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    90 9f 18 19 81 88 ff ff 90 9f 18 19 81 88 ff ff  ................
  backtrace:
    [<0000000004286457>] kmalloc include/linux/slab.h:554 [inline]
    [<0000000004286457>] kzalloc include/linux/slab.h:666 [inline]
    [<0000000004286457>] nf_tables_addchain.constprop.0+0x414/0x720 net/netfilter/nf_tables_api.c:2006
    [<0000000064582dc8>] nf_tables_newchain+0x74c/0x9d0 net/netfilter/nf_tables_api.c:2316
    [<000000009af54f85>] nfnetlink_rcv_batch+0x2fb/0x9e0 net/netfilter/nfnetlink.c:434
    [<000000000edcf8ff>] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:544 [inline]
    [<000000000edcf8ff>] nfnetlink_rcv+0x182/0x1b0 net/netfilter/nfnetlink.c:562
    [<00000000d8cb87ba>] netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
    [<00000000d8cb87ba>] netlink_unicast+0x2b6/0x3c0 net/netlink/af_netlink.c:1330
    [<00000000e133d3d8>] netlink_sendmsg+0x2ba/0x570 net/netlink/af_netlink.c:1919
    [<000000003f4dae42>] sock_sendmsg_nosec net/socket.c:651 [inline]
    [<000000003f4dae42>] sock_sendmsg+0x4c/0x60 net/socket.c:671
    [<00000000a38aa29c>] ____sys_sendmsg+0x2c4/0x2f0 net/socket.c:2359
    [<00000000a06b2c98>] ___sys_sendmsg+0x81/0xc0 net/socket.c:2413
    [<00000000b3d1da45>] __sys_sendmsg+0x77/0xe0 net/socket.c:2446
    [<00000000e1124972>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
    [<00000000f18a8a31>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



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