syzbot has found a reproducer for the following issue on: HEAD commit: e4fb79c7 Add linux-next specific files for 20201008 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=17dda29f900000 kernel config: https://syzkaller.appspot.com/x/.config?x=568d41fe4341ed0f dashboard link: https://syzkaller.appspot.com/bug?extid=cdcbdc0bd42e559b52b9 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14860568500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16367de7900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+cdcbdc0bd42e559b52b9@xxxxxxxxxxxxxxxxxxxxxxxxx ================================ WARNING: inconsistent lock state 5.9.0-rc8-next-20201008-syzkaller #0 Not tainted -------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/0/0 [HC0[0]:SC1[1]:HE0:SE0] takes: ffff888025f65018 (&xa->xa_lock#7){+.?.}-{2:2}, at: xa_destroy+0xaa/0x350 lib/xarray.c:2205 {SOFTIRQ-ON-W} state was registered at: lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5419 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] io_uring_add_task_file fs/io_uring.c:8607 [inline] io_uring_add_task_file+0x207/0x430 fs/io_uring.c:8590 io_uring_get_fd fs/io_uring.c:9116 [inline] io_uring_create fs/io_uring.c:9280 [inline] io_uring_setup+0x2727/0x3660 fs/io_uring.c:9314 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 irq event stamp: 120141 hardirqs last enabled at (120140): [<ffffffff8847f0df>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (120140): [<ffffffff8847f0df>] _raw_spin_unlock_irqrestore+0x6f/0x90 kernel/locking/spinlock.c:191 hardirqs last disabled at (120141): [<ffffffff8847f6c9>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (120141): [<ffffffff8847f6c9>] _raw_spin_lock_irqsave+0xa9/0xd0 kernel/locking/spinlock.c:159 softirqs last enabled at (119956): [<ffffffff814731af>] irq_enter_rcu+0xcf/0xf0 kernel/softirq.c:360 softirqs last disabled at (119957): [<ffffffff88600f2f>] asm_call_irq_on_stack+0xf/0x20 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&xa->xa_lock#7); <Interrupt> lock(&xa->xa_lock#7); *** DEADLOCK *** 1 lock held by swapper/0/0: #0: ffffffff8a554c80 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2474 [inline] #0: ffffffff8a554c80 (rcu_callback){....}-{0:0}, at: rcu_core+0x5d8/0x1240 kernel/rcu/tree.c:2718 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.9.0-rc8-next-20201008-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x198/0x1fb lib/dump_stack.c:118 print_usage_bug kernel/locking/lockdep.c:3715 [inline] valid_state kernel/locking/lockdep.c:3726 [inline] mark_lock_irq kernel/locking/lockdep.c:3929 [inline] mark_lock.cold+0x32/0x74 kernel/locking/lockdep.c:4396 mark_usage kernel/locking/lockdep.c:4281 [inline] __lock_acquire+0x118a/0x56d0 kernel/locking/lockdep.c:4771 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5419 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x94/0xd0 kernel/locking/spinlock.c:159 xa_destroy+0xaa/0x350 lib/xarray.c:2205 __io_uring_free+0x60/0xc0 fs/io_uring.c:7693 io_uring_free include/linux/io_uring.h:40 [inline] __put_task_struct+0xff/0x3f0 kernel/fork.c:732 put_task_struct include/linux/sched/task.h:111 [inline] delayed_put_task_struct+0x1f6/0x340 kernel/exit.c:172 rcu_do_batch kernel/rcu/tree.c:2484 [inline] rcu_core+0x645/0x1240 kernel/rcu/tree.c:2718 __do_softirq+0x203/0xab6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 </IRQ> __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x9b/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x235/0x280 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 89 ef e8 b5 62 6f f9 e9 86 fe ff ff 48 89 df e8 a8 62 6f f9 e9 7b ff ff ff cc cc cc e9 07 00 00 00 0f 00 2d 54 08 61 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d 44 08 61 00 f4 c3 cc cc 55 53 e8 09 RSP: 0018:ffffffff8a207d48 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff176a7c1 RDX: ffffffff8a29ce40 RSI: ffffffff8847e5c3 RDI: 0000000000000000 RBP: ffff888012d2e064 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffff888012d2e000 R14: ffff888012d2e064 R15: ffff8881339b2004 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] acpi_idle_do_entry+0x1e8/0x330 drivers/acpi/processor_idle.c:517 acpi_idle_enter+0x35a/0x550 drivers/acpi/processor_idle.c:648 cpuidle_enter_state+0x1ab/0xdb0 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:132 [inline] cpuidle_idle_call kernel/sched/idle.c:213 [inline] do_idle+0x48e/0x730 kernel/sched/idle.c:273 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:369 start_kernel+0x490/0x4b1 init/main.c:1049 secondary_startup_64_no_verify+0xa6/0xab
