================================ WARNING: inconsistent lock state 6.1.0-rc5-syzkaller-00146-g30f158740984 #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-R} usage. ksoftirqd/0/15 [HC0[0]:SC1[3]:HE1:SE0] takes: ffff88804a6a6fb8 (k-clock-AF_INET){+++-}-{2:2}, at: smc_fback_state_change+0x20/0xc0 net/smc/af_smc.c:799 {SOFTIRQ-ON-W} state was registered at: 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+0x228/0x320 net/netlink/genetlink.c:756 genl_family_rcv_msg net/netlink/genetlink.c:833 [inline] genl_rcv_msg+0x445/0x780 net/netlink/genetlink.c:850 netlink_rcv_skb+0x157/0x430 net/netlink/af_netlink.c:2540 genl_rcv+0x28/0x40 net/netlink/genetlink.c:861 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2482 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2536 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2565 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: 271950 hardirqs last enabled at (271950): [] __local_bh_enable_ip+0xa4/0x130 kernel/softirq.c:401 hardirqs last disabled at (271949): [] __local_bh_enable_ip+0xc7/0x130 kernel/softirq.c:378 softirqs last enabled at (271872): [] run_ksoftirqd kernel/softirq.c:934 [inline] softirqs last enabled at (271872): [] run_ksoftirqd+0x31/0x60 kernel/softirq.c:926 softirqs last disabled at (271879): [] run_ksoftirqd kernel/softirq.c:934 [inline] softirqs last disabled at (271879): [] run_ksoftirqd+0x31/0x60 kernel/softirq.c:926 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/0/15: #0: ffffffff8c58fc40 (rcu_read_lock){....}-{1:2}, at: __skb_unlink include/linux/skbuff.h:2324 [inline] #0: ffffffff8c58fc40 (rcu_read_lock){....}-{1:2}, at: __skb_dequeue include/linux/skbuff.h:2339 [inline] #0: ffffffff8c58fc40 (rcu_read_lock){....}-{1:2}, at: process_backlog+0x38f/0x810 net/core/dev.c:5929 #1: ffffffff8c58fc40 (rcu_read_lock){....}-{1:2}, at: __skb_pull include/linux/skbuff.h:2609 [inline] #1: ffffffff8c58fc40 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x20a/0x4c0 net/ipv4/ip_input.c:230 #2: ffff88804a6a6cb0 (k-slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x3429/0x3980 net/ipv4/tcp_ipv4.c:2098 stack backtrace: CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.1.0-rc5-syzkaller-00146-g30f158740984 #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:3963 [inline] valid_state kernel/locking/lockdep.c:3975 [inline] mark_lock_irq kernel/locking/lockdep.c:4178 [inline] mark_lock.part.0.cold+0x18/0xd8 kernel/locking/lockdep.c:4634 mark_lock kernel/locking/lockdep.c:4598 [inline] mark_usage kernel/locking/lockdep.c:4521 [inline] __lock_acquire+0x14dc/0x56d0 kernel/locking/lockdep.c:5009 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_state_change+0x20/0xc0 net/smc/af_smc.c:799 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:6292 [inline] tcp_rcv_state_process+0xd7a/0x49a0 net/ipv4/tcp_input.c:6489 tcp_v4_do_rcv+0x33d/0x9b0 net/ipv4/tcp_ipv4.c:1704 tcp_v4_rcv+0x36ad/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:455 [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:5489 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5603 process_backlog+0x3e4/0x810 net/core/dev.c:5931 __napi_poll+0xb8/0x770 net/core/dev.c:6498 napi_poll net/core/dev.c:6565 [inline] net_rx_action+0xa00/0xde0 net/core/dev.c:6676 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x659/0xa20 kernel/smpboot.c:164 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306