================================ WARNING: inconsistent lock state 6.1.0-rc6-syzkaller-32653-g65762d97e6fa #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-R} usage. ksoftirqd/1/20 [HC0[0]:SC1[3]:HE1:SE0] takes: ffff0000cff183b8 (k-clock-AF_INET){+++-}-{2:2}, at: smc_fback_state_change+0x28/0x78 net/smc/af_smc.c:799 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline] _raw_write_lock+0x54/0x6c kernel/locking/spinlock.c:300 l2tp_tunnel_register+0x354/0x79c net/l2tp/l2tp_core.c:1477 l2tp_nl_cmd_tunnel_create+0x1f8/0x330 net/l2tp/l2tp_netlink.c:245 genl_family_rcv_msg_doit net/netlink/genetlink.c:756 [inline] genl_family_rcv_msg net/netlink/genetlink.c:833 [inline] genl_rcv_msg+0x458/0x4f4 net/netlink/genetlink.c:850 netlink_rcv_skb+0xe8/0x1d4 net/netlink/af_netlink.c:2540 genl_rcv+0x38/0x50 net/netlink/genetlink.c:861 netlink_unicast_kernel+0xfc/0x1dc net/netlink/af_netlink.c:1319 netlink_unicast+0x164/0x248 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x484/0x584 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] ____sys_sendmsg+0x2f8/0x440 net/socket.c:2482 ___sys_sendmsg net/socket.c:2536 [inline] __sys_sendmsg+0x1ac/0x228 net/socket.c:2565 __do_sys_sendmsg net/socket.c:2574 [inline] __se_sys_sendmsg net/socket.c:2572 [inline] __arm64_sys_sendmsg+0x2c/0x3c net/socket.c:2572 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 irq event stamp: 188662 hardirqs last enabled at (188662): [] __local_bh_enable_ip+0x13c/0x1a4 kernel/softirq.c:401 hardirqs last disabled at (188661): [] __local_bh_enable_ip+0xc4/0x1a4 kernel/softirq.c:378 softirqs last enabled at (188534): [] _stext+0x2e4/0x37c softirqs last disabled at (188539): [] run_ksoftirqd+0x4c/0x21c kernel/softirq.c:934 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(k-clock-AF_INET); lock(k-clock-AF_INET ); *** DEADLOCK *** 3 locks held by ksoftirqd/1/20: #0: ffff80000d4a4640 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:303 #1: ffff80000d4a4640 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:303 #2: ffff0000cff180b0 (k-slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x1034/0x11e8 net/ipv4/tcp_ipv4.c:2098 stack backtrace: CPU: 1 PID: 20 Comm: ksoftirqd/1 Not tainted 6.1.0-rc6-syzkaller-32653-g65762d97e6fa #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_usage_bug+0x39c/0x3cc kernel/locking/lockdep.c:3963 mark_lock_irq+0x4a8/0x4b4 mark_lock+0x154/0x1b4 kernel/locking/lockdep.c:4634 __lock_acquire+0x5a0/0x3084 kernel/locking/lockdep.c:5009 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 __raw_read_lock_bh include/linux/rwlock_api_smp.h:176 [inline] _raw_read_lock_bh+0x64/0x7c kernel/locking/spinlock.c:252 smc_fback_state_change+0x28/0x78 net/smc/af_smc.c:799 tcp_rcv_synsent_state_process+0x7bc/0x974 net/ipv4/tcp_input.c:6292 tcp_rcv_state_process+0x118/0xe60 net/ipv4/tcp_input.c:6489 tcp_v4_do_rcv+0x3f0/0x51c net/ipv4/tcp_ipv4.c:1704 tcp_v4_rcv+0x1090/0x11e8 net/ipv4/tcp_ipv4.c:2102 ip_protocol_deliver_rcu+0x224/0x414 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x124/0x200 net/ipv4/ip_input.c:233 NF_HOOK include/linux/netfilter.h:302 [inline] ip_local_deliver+0xd0/0xf4 net/ipv4/ip_input.c:254 dst_input include/net/dst.h:455 [inline] ip_rcv_finish+0x16c/0x190 net/ipv4/ip_input.c:444 NF_HOOK include/linux/netfilter.h:302 [inline] ip_rcv+0x80/0xb0 net/ipv4/ip_input.c:564 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x70/0x14c net/core/dev.c:5603 process_backlog+0x240/0x388 net/core/dev.c:5931 __napi_poll+0x5c/0x24c net/core/dev.c:6498 napi_poll+0x110/0x484 net/core/dev.c:6565 net_rx_action+0x18c/0x414 net/core/dev.c:6676 _stext+0x168/0x37c run_ksoftirqd+0x4c/0x21c kernel/softirq.c:934 smpboot_thread_fn+0x248/0x3ec kernel/smpboot.c:164 kthread+0x12c/0x158 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:863