================================ WARNING: inconsistent lock state 4.20.0+ #389 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. syz-executor820/11913 [HC0[0]:SC0[0]:HE1:SE1] takes: 000000003a3617a7 (slock-AF_NETROM){+.?.}, at: spin_lock include/linux/spinlock.h:329 [inline] 000000003a3617a7 (slock-AF_NETROM){+.?.}, at: nr_find_socket+0x113/0x160 net/netrom/af_netrom.c:177 {IN-SOFTIRQ-W} state was registered at: lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] nr_find_listener net/netrom/af_netrom.c:156 [inline] nr_rx_frame+0x5f8/0x1db0 net/netrom/af_netrom.c:955 nr_loopback_timer+0x79/0x160 net/netrom/nr_loopback.c:62 call_timer_fn+0x272/0x920 kernel/time/timer.c:1325 expire_timers kernel/time/timer.c:1362 [inline] __run_timers+0x7e5/0xc70 kernel/time/timer.c:1681 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694 __do_softirq+0x30c/0xb2e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1061 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] lock_acquire+0x268/0x520 kernel/locking/lockdep.c:3847 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2d/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] do_anonymous_page mm/memory.c:2947 [inline] handle_pte_fault mm/memory.c:3763 [inline] __handle_mm_fault+0x298c/0x5670 mm/memory.c:3889 handle_mm_fault+0x54f/0xc70 mm/memory.c:3926 do_user_addr_fault arch/x86/mm/fault.c:1423 [inline] __do_page_fault+0x5e8/0xe60 arch/x86/mm/fault.c:1489 do_page_fault+0xf2/0x7e0 arch/x86/mm/fault.c:1520 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1143 irq event stamp: 294 hardirqs last enabled at (292): [] trace_hardirqs_on_thunk+0x1a/0x1c hardirqs last disabled at (293): [] __local_bh_enable_ip+0x120/0x260 kernel/softirq.c:171 softirqs last enabled at (294): [] spin_unlock_bh include/linux/spinlock.h:374 [inline] softirqs last enabled at (294): [] nr_find_socket+0x128/0x160 net/netrom/af_netrom.c:183 softirqs last disabled at (290): [] spin_lock_bh include/linux/spinlock.h:334 [inline] softirqs last disabled at (290): [] nr_find_socket+0x24/0x160 net/netrom/af_netrom.c:172 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(slock-AF_NETROM); lock(slock-AF_NETROM); *** DEADLOCK *** 1 lock held by syz-executor820/11913: #0: 000000003a3617a7 (slock-AF_NETROM){+.?.}, at: spin_lock include/linux/spinlock.h:329 [inline] #0: 000000003a3617a7 (slock-AF_NETROM){+.?.}, at: nr_find_socket+0x113/0x160 net/netrom/af_netrom.c:177 stack backtrace: CPU: 0 PID: 11913 Comm: syz-executor820 Not tainted 4.20.0+ #389 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113 print_usage_bug.cold.59+0x320/0x41a kernel/locking/lockdep.c:2472 valid_state kernel/locking/lockdep.c:2485 [inline] mark_lock_irq kernel/locking/lockdep.c:2679 [inline] mark_lock+0x1114/0x1cc0 kernel/locking/lockdep.c:3059 mark_held_locks+0xc7/0x130 kernel/locking/lockdep.c:2737 __trace_hardirqs_on_caller kernel/locking/lockdep.c:2766 [inline] lockdep_hardirqs_on+0x421/0x5c0 kernel/locking/lockdep.c:2811 trace_hardirqs_on+0xbd/0x310 kernel/trace/trace_preemptirq.c:30 __local_bh_enable_ip+0x160/0x260 kernel/softirq.c:194 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:200 spin_unlock_bh include/linux/spinlock.h:374 [inline] nr_find_socket+0x128/0x160 net/netrom/af_netrom.c:183 nr_find_next_circuit+0x71/0x90 net/netrom/af_netrom.c:225 nr_connect+0x6cb/0x1350 net/netrom/af_netrom.c:704 __sys_connect+0x37d/0x4c0 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1672 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4482e9 Code: e8 cc e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 0f 83 0b 01 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6fed5b1cc8 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00000000006ddc28 RCX: 00000000004482e9 RDX: 0000000000000048 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00000000006ddc20 R08: 00007ffd44256f4f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006ddc2c R13: 00007ffd44256f4f R14: 00007f6fed5b29c0 R15: 00000000006ddc20