================================ WARNING: inconsistent lock state 6.1.0-rc5-syzkaller-01477-g7a168f560e3c #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-R} -> {SOFTIRQ-ON-W} usage. syz-executor.4/17572 [HC0[0]:SC0[0]:HE1:SE1] takes: ffff88807cf53e38 (k-clock-AF_INET){+++-}-{2:2}, at: l2tp_tunnel_register+0x126/0x1210 net/l2tp/l2tp_core.c:1477 {IN-SOFTIRQ-R} state was registered at: lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x3f/0x70 kernel/locking/spinlock.c:252 smc_fback_write_space+0x20/0xc0 net/smc/af_smc.c:823 tcp_new_space net/ipv4/tcp_input.c:5482 [inline] tcp_check_space+0x11b/0x810 net/ipv4/tcp_input.c:5501 tcp_data_snd_check net/ipv4/tcp_input.c:5510 [inline] tcp_rcv_established+0x93e/0x2230 net/ipv4/tcp_input.c:6018 tcp_v4_do_rcv+0x670/0x9b0 net/ipv4/tcp_ipv4.c:1681 tcp_v4_rcv+0x36ae/0x3980 net/ipv4/tcp_ipv4.c:2102 ip_protocol_deliver_rcu+0x9f/0x7c0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2ec/0x4c0 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:302 [inline] NF_HOOK include/linux/netfilter.h:296 [inline] ip_local_deliver+0x1ae/0x200 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:454 [inline] ip_rcv_finish+0x1cf/0x2f0 net/ipv4/ip_input.c:444 NF_HOOK include/linux/netfilter.h:302 [inline] NF_HOOK include/linux/netfilter.h:296 [inline] ip_rcv+0xae/0xd0 net/ipv4/ip_input.c:564 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5482 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5596 process_backlog+0x3e4/0x810 net/core/dev.c:5924 __napi_poll+0xb8/0x770 net/core/dev.c:6485 napi_poll net/core/dev.c:6552 [inline] net_rx_action+0xa00/0xde0 net/core/dev.c:6663 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 do_softirq.part.0+0xde/0x130 kernel/softirq.c:472 do_softirq kernel/softirq.c:464 [inline] __local_bh_enable_ip+0x106/0x130 kernel/softirq.c:396 sk_stream_wait_memory+0x6f6/0xf20 net/core/stream.c:145 tcp_sendmsg_locked+0x94c/0x2960 net/ipv4/tcp.c:1445 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1483 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:827 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd irq event stamp: 811 hardirqs last enabled at (811): [] __local_bh_enable_ip+0xa4/0x130 kernel/softirq.c:401 hardirqs last disabled at (809): [] __local_bh_enable_ip+0xc7/0x130 kernel/softirq.c:378 softirqs last enabled at (810): [] l2tp_ip_connect+0xee/0x340 net/l2tp/l2tp_ip.c:338 softirqs last disabled at (808): [] spin_lock_bh include/linux/spinlock.h:355 [inline] softirqs last disabled at (808): [] release_sock+0x1f/0x1b0 net/core/sock.c:3474 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-clock-AF_INET); lock(k-clock-AF_INET); *** DEADLOCK *** 2 locks held by syz-executor.4/17572: #0: ffffffff8df55d70 (cb_lock){++++}-{3:3}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1075 #1: ffffffff8df55e28 (genl_mutex){+.+.}-{3:3}, at: genl_lock net/netlink/genetlink.c:33 [inline] #1: ffffffff8df55e28 (genl_mutex){+.+.}-{3:3}, at: genl_rcv_msg+0x51a/0x7e0 net/netlink/genetlink.c:1063 stack backtrace: CPU: 0 PID: 17572 Comm: syz-executor.4 Not tainted 6.1.0-rc5-syzkaller-01477-g7a168f560e3c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_usage_bug kernel/locking/lockdep.c:222 [inline] valid_state kernel/locking/lockdep.c:3975 [inline] mark_lock_irq kernel/locking/lockdep.c:4184 [inline] mark_lock.part.0.cold+0x3a/0xd8 kernel/locking/lockdep.c:4634 mark_lock kernel/locking/lockdep.c:4598 [inline] mark_usage kernel/locking/lockdep.c:4547 [inline] __lock_acquire+0x893/0x56d0 kernel/locking/lockdep.c:5009 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline] _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300 l2tp_tunnel_register+0x126/0x1210 net/l2tp/l2tp_core.c:1477 l2tp_nl_cmd_tunnel_create+0x3d6/0x8b0 net/l2tp/l2tp_netlink.c:245 genl_family_rcv_msg_doit.isra.0+0x1e6/0x2d0 net/netlink/genetlink.c:968 genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline] genl_rcv_msg+0x4ff/0x7e0 net/netlink/genetlink.c:1065 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f26e208c0d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f26e2eb9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f26e21ac050 RCX: 00007f26e208c0d9 RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000006 RBP: 00007f26e20e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff39bde83f R14: 00007f26e2eb9300 R15: 0000000000022000