memory leak in nf_tables_parse_netdev_hooks (3)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    7ae77150 Merge tag 'powerpc-5.8-1' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1741f5f2100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9a1aa05456dfd557
dashboard link: https://syzkaller.appspot.com/bug?extid=eb9d5924c51d6d59e094
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=126f5446100000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=177f16fe100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+eb9d5924c51d6d59e094@xxxxxxxxxxxxxxxxxxxxxxxxx

executing program
BUG: memory leak
unreferenced object 0xffff88811589cd80 (size 96):
  comm "syz-executor337", pid 6663, jiffies 4294942418 (age 13.980s)
  hex dump (first 32 bytes):
    00 c9 89 15 81 88 ff ff 68 f9 ff 00 00 c9 ff ff  ........h.......
    00 cd 89 15 81 88 ff ff 60 52 c5 82 ff ff ff ff  ........`R......
  backtrace:
    [<00000000104a1f01>] kmalloc include/linux/slab.h:555 [inline]
    [<00000000104a1f01>] nft_netdev_hook_alloc+0x3b/0xd0 net/netfilter/nf_tables_api.c:1659
    [<000000003bc42f25>] nf_tables_parse_netdev_hooks+0x94/0x210 net/netfilter/nf_tables_api.c:1709
    [<000000004b6a9590>] nft_flowtable_parse_hook+0x101/0x1d0 net/netfilter/nf_tables_api.c:6243
    [<000000004204916e>] nft_delflowtable_hook net/netfilter/nf_tables_api.c:6562 [inline]
    [<000000004204916e>] nf_tables_delflowtable+0x249/0x4a0 net/netfilter/nf_tables_api.c:6640
    [<00000000fa0bd6d2>] nfnetlink_rcv_batch+0x2f3/0x810 net/netfilter/nfnetlink.c:433
    [<000000004d4e8df7>] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline]
    [<000000004d4e8df7>] nfnetlink_rcv+0x183/0x1b0 net/netfilter/nfnetlink.c:561
    [<000000001710060c>] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
    [<000000001710060c>] netlink_unicast+0x20a/0x2f0 net/netlink/af_netlink.c:1329
    [<00000000bb814b80>] netlink_sendmsg+0x2b5/0x560 net/netlink/af_netlink.c:1918
    [<00000000eb7a00fe>] sock_sendmsg_nosec net/socket.c:652 [inline]
    [<00000000eb7a00fe>] sock_sendmsg+0x4c/0x60 net/socket.c:672
    [<000000008cc37c52>] ____sys_sendmsg+0x2c4/0x2f0 net/socket.c:2352
    [<00000000b882e46e>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2406
    [<00000000870e7750>] __sys_sendmsg+0x77/0xe0 net/socket.c:2439
    [<000000002b222e75>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
    [<00000000356e1a8a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff88811589c900 (size 96):
  comm "syz-executor337", pid 6663, jiffies 4294942418 (age 13.980s)
  hex dump (first 32 bytes):
    68 f9 ff 00 00 c9 ff ff 80 cd 89 15 81 88 ff ff  h...............
    00 00 00 00 00 00 00 00 60 52 c5 82 ff ff ff ff  ........`R......
  backtrace:
    [<00000000104a1f01>] kmalloc include/linux/slab.h:555 [inline]
    [<00000000104a1f01>] nft_netdev_hook_alloc+0x3b/0xd0 net/netfilter/nf_tables_api.c:1659
    [<000000003bc42f25>] nf_tables_parse_netdev_hooks+0x94/0x210 net/netfilter/nf_tables_api.c:1709
    [<000000004b6a9590>] nft_flowtable_parse_hook+0x101/0x1d0 net/netfilter/nf_tables_api.c:6243
    [<000000004204916e>] nft_delflowtable_hook net/netfilter/nf_tables_api.c:6562 [inline]
    [<000000004204916e>] nf_tables_delflowtable+0x249/0x4a0 net/netfilter/nf_tables_api.c:6640
    [<00000000fa0bd6d2>] nfnetlink_rcv_batch+0x2f3/0x810 net/netfilter/nfnetlink.c:433
    [<000000004d4e8df7>] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline]
    [<000000004d4e8df7>] nfnetlink_rcv+0x183/0x1b0 net/netfilter/nfnetlink.c:561
    [<000000001710060c>] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
    [<000000001710060c>] netlink_unicast+0x20a/0x2f0 net/netlink/af_netlink.c:1329
    [<00000000bb814b80>] netlink_sendmsg+0x2b5/0x560 net/netlink/af_netlink.c:1918
    [<00000000eb7a00fe>] sock_sendmsg_nosec net/socket.c:652 [inline]
    [<00000000eb7a00fe>] sock_sendmsg+0x4c/0x60 net/socket.c:672
    [<000000008cc37c52>] ____sys_sendmsg+0x2c4/0x2f0 net/socket.c:2352
    [<00000000b882e46e>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2406
    [<00000000870e7750>] __sys_sendmsg+0x77/0xe0 net/socket.c:2439
    [<000000002b222e75>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
    [<00000000356e1a8a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

BUG: memory leak
unreferenced object 0xffff888115961800 (size 96):
  comm "syz-executor337", pid 6664, jiffies 4294943010 (age 8.060s)
  hex dump (first 32 bytes):
    00 19 96 15 81 88 ff ff 68 f9 ff 00 00 c9 ff ff  ........h.......
    00 00 00 00 00 00 00 00 60 52 c5 82 ff ff ff ff  ........`R......
  backtrace:
    [<00000000104a1f01>] kmalloc include/linux/slab.h:555 [inline]
    [<00000000104a1f01>] nft_netdev_hook_alloc+0x3b/0xd0 net/netfilter/nf_tables_api.c:1659
    [<000000003bc42f25>] nf_tables_parse_netdev_hooks+0x94/0x210 net/netfilter/nf_tables_api.c:1709
    [<000000004b6a9590>] nft_flowtable_parse_hook+0x101/0x1d0 net/netfilter/nf_tables_api.c:6243
    [<000000004204916e>] nft_delflowtable_hook net/netfilter/nf_tables_api.c:6562 [inline]
    [<000000004204916e>] nf_tables_delflowtable+0x249/0x4a0 net/netfilter/nf_tables_api.c:6640
    [<00000000fa0bd6d2>] nfnetlink_rcv_batch+0x2f3/0x810 net/netfilter/nfnetlink.c:433
    [<000000004d4e8df7>] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:543 [inline]
    [<000000004d4e8df7>] nfnetlink_rcv+0x183/0x1b0 net/netfilter/nfnetlink.c:561
    [<000000001710060c>] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
    [<000000001710060c>] netlink_unicast+0x20a/0x2f0 net/netlink/af_netlink.c:1329
    [<00000000bb814b80>] netlink_sendmsg+0x2b5/0x560 net/netlink/af_netlink.c:1918
    [<00000000eb7a00fe>] sock_sendmsg_nosec net/socket.c:652 [inline]
    [<00000000eb7a00fe>] sock_sendmsg+0x4c/0x60 net/socket.c:672
    [<000000008cc37c52>] ____sys_sendmsg+0x2c4/0x2f0 net/socket.c:2352
    [<00000000b882e46e>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2406
    [<00000000870e7750>] __sys_sendmsg+0x77/0xe0 net/socket.c:2439
    [<000000002b222e75>] do_syscall_64+0x6e/0x220 arch/x86/entry/common.c:295
    [<00000000356e1a8a>] entry_SYSCALL_64_after_hwframe+0x44/0xa9



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