============================= [ BUG: Invalid wait context ] syzkaller #0 Not tainted ----------------------------- kworker/u32:8/1152 is trying to lock: ffff88802b935430 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x254/0xeb0 arch/x86/kvm/xen.c:1820 other info that might help us debug this: context-{2:2} 7 locks held by kworker/u32:8/1152: #0: ffff88801b491948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90006547d00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff88803248d250 (&devlink->lock_key#3){+.+.}-{4:4}, at: nsim_dev_trap_report_work+0x56/0xcf0 drivers/net/netdevsim/dev.c:853 #3: ffff8880243930e0 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #3: ffff8880243930e0 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report drivers/net/netdevsim/dev.c:806 [inline] #3: ffff8880243930e0 (&nsim_trap_data->trap_lock){+.+.}-{3:3}, at: nsim_dev_trap_report_work+0x1cd/0xcf0 drivers/net/netdevsim/dev.c:866 #4: ffffffff8e3c4340 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3c4340 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2599 [inline] #4: ffffffff8e3c4340 (rcu_callback){....}-{0:0}, at: rcu_core+0x73d/0x1530 kernel/rcu/tree.c:2861 #5: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #5: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #5: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x20a0 arch/x86/kernel/unwind_orc.c:479 #6: ffff88802b935980 (&kvm->srcu){.?.?}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #6: ffff88802b935980 (&kvm->srcu){.?.?}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #6: ffff88802b935980 (&kvm->srcu){.?.?}-{0:0}, at: kvm_xen_set_evtchn_fast+0x23a/0xeb0 arch/x86/kvm/xen.c:1818 stack backtrace: CPU: 0 UID: 0 PID: 1152 Comm: kworker/u32:8 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events_unbound nsim_dev_trap_report_work Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xa12/0x1c90 kernel/locking/lockdep.c:5187 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:236 kvm_xen_set_evtchn_fast+0x254/0xeb0 arch/x86/kvm/xen.c:1820 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x5ed/0xad0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline] RIP: 0010:unwind_next_frame+0x161d/0x20a0 arch/x86/kernel/unwind_orc.c:665 Code: cb f9 ff ff e8 c4 65 b9 00 e9 c1 f9 ff ff 48 b8 00 00 00 00 00 fc ff df 48 8b 14 24 48 c1 ea 03 80 3c 02 00 0f 85 56 05 00 00 <49> 8d 7d 08 49 8b 5d 38 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 RSP: 0018:ffffc900000079e0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000000002 RCX: ffffc90000008000 RDX: 1ffff92000000f51 RSI: ffffc90000007f10 RDI: ffffc90000007a90 RBP: 0000000000000009 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 000000000000a382 R12: ffffc90000007aa0 R13: ffffc90000007a50 R14: ffffc90000007f40 R15: ffffc90000007a84 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2523 [inline] slab_free_after_rcu_debug+0x110/0x340 mm/slub.c:6669 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x1530 kernel/rcu/tree.c:2861 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:510 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:835 [inline] nsim_dev_trap_report_work+0x8b5/0xcf0 drivers/net/netdevsim/dev.c:866 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess), 4 bytes skipped: 0: e8 c4 65 b9 00 call 0xb965c9 5: e9 c1 f9 ff ff jmp 0xfffff9cb a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 11: fc ff df 14: 48 8b 14 24 mov (%rsp),%rdx 18: 48 c1 ea 03 shr $0x3,%rdx 1c: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 20: 0f 85 56 05 00 00 jne 0x57c * 26: 49 8d 7d 08 lea 0x8(%r13),%rdi <-- trapping instruction 2a: 49 8b 5d 38 mov 0x38(%r13),%rbx 2e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 35: fc ff df 38: 48 89 fa mov %rdi,%rdx 3b: 48 rex.W