======================================================== WARNING: possible irq lock inversion dependency detected 5.8.0-syzkaller #0 Not tainted -------------------------------------------------------- syz-executor046/6843 just changed the state of lock: ffff8880a6b534d8 (&ctx->completion_lock){-...}-{2:2}, at: io_timeout_fn+0x6c/0x3f0 fs/io_uring.c:4999 but this lock took another, HARDIRQ-unsafe lock in the past: (&fs->lock){+.+.}-{2:2} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs->lock); local_irq_disable(); lock(&ctx->completion_lock); lock(&fs->lock); lock(&ctx->completion_lock); *** DEADLOCK *** 1 lock held by syz-executor046/6843: #0: ffff8880a6b53428 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0xdb7/0x1ae0 fs/io_uring.c:8035 the shortest dependencies between 2nd lock and 1st lock: -> (&fs->lock){+.+.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __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] set_fs_pwd+0x85/0x290 fs/fs_struct.c:39 init_chdir+0x106/0x14e fs/init.c:54 devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 SOFTIRQ-ON-W at: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __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] set_fs_pwd+0x85/0x290 fs/fs_struct.c:39 init_chdir+0x106/0x14e fs/init.c:54 devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 INITIAL USE at: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __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] set_fs_pwd+0x85/0x290 fs/fs_struct.c:39 init_chdir+0x106/0x14e fs/init.c:54 devtmpfs_setup drivers/base/devtmpfs.c:415 [inline] devtmpfsd+0x76/0x333 drivers/base/devtmpfs.c:430 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 } ... key at: [] __key.1+0x0/0x40 ... acquired at: __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_req_clean_work fs/io_uring.c:1126 [inline] io_dismantle_req+0x3ec/0x9e0 fs/io_uring.c:1544 __io_free_req+0x16/0x3c0 fs/io_uring.c:1562 __io_double_put_req fs/io_uring.c:1909 [inline] __io_fail_links+0x433/0x5b0 fs/io_uring.c:1659 io_fail_links fs/io_uring.c:1675 [inline] __io_req_find_next+0x368/0x460 fs/io_uring.c:1698 io_req_find_next fs/io_uring.c:1706 [inline] io_steal_work fs/io_uring.c:1897 [inline] io_wq_submit_work+0x33c/0x3d0 fs/io_uring.c:5792 io_worker_handle_work+0xa45/0x13f0 fs/io-wq.c:527 io_wqe_worker+0xbf0/0x10e0 fs/io-wq.c:569 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 -> (&ctx->completion_lock){-...}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 io_timeout_fn+0x6c/0x3f0 fs/io_uring.c:4999 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1096 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1090 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 arch_local_irq_enable arch/x86/include/asm/paravirt.h:780 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 spin_unlock_irq include/linux/spinlock.h:404 [inline] io_timeout fs/io_uring.c:5162 [inline] io_issue_sqe+0x2de6/0x60d0 fs/io_uring.c:5594 __io_queue_sqe+0x284/0x1190 fs/io_uring.c:5981 io_queue_sqe+0x73e/0x1130 fs/io_uring.c:6060 io_submit_sqe fs/io_uring.c:6130 [inline] io_submit_sqes+0x1794/0x2380 fs/io_uring.c:6327 __do_sys_io_uring_enter+0xdc7/0x1ae0 fs/io_uring.c:8036 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INITIAL USE at: lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 io_cqring_add_event fs/io_uring.c:1419 [inline] __io_req_complete fs/io_uring.c:1458 [inline] __io_req_complete fs/io_uring.c:1454 [inline] io_req_complete fs/io_uring.c:1472 [inline] io_madvise fs/io_uring.c:3737 [inline] io_issue_sqe+0xcfd/0x60d0 fs/io_uring.c:5682 io_wq_submit_work+0x183/0x3d0 fs/io_uring.c:5775 io_worker_handle_work+0xa45/0x13f0 fs/io-wq.c:527 io_wqe_worker+0xbf0/0x10e0 fs/io-wq.c:569 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 } ... key at: [] __key.9+0x0/0x40 ... acquired at: mark_lock_irq kernel/locking/lockdep.c:3568 [inline] mark_lock+0x54b/0x1710 kernel/locking/lockdep.c:4006 mark_usage kernel/locking/lockdep.c:3902 [inline] __lock_acquire+0x13ad/0x5640 kernel/locking/lockdep.c:4380 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 io_timeout_fn+0x6c/0x3f0 fs/io_uring.c:4999 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1096 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1090 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 arch_local_irq_enable arch/x86/include/asm/paravirt.h:780 [inline] __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 spin_unlock_irq include/linux/spinlock.h:404 [inline] io_timeout fs/io_uring.c:5162 [inline] io_issue_sqe+0x2de6/0x60d0 fs/io_uring.c:5594 __io_queue_sqe+0x284/0x1190 fs/io_uring.c:5981 io_queue_sqe+0x73e/0x1130 fs/io_uring.c:6060 io_submit_sqe fs/io_uring.c:6130 [inline] io_submit_sqes+0x1794/0x2380 fs/io_uring.c:6327 __do_sys_io_uring_enter+0xdc7/0x1ae0 fs/io_uring.c:8036 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 stack backtrace: CPU: 0 PID: 6843 Comm: syz-executor046 Not tainted 5.8.0-syzkaller #0 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+0x18f/0x20d lib/dump_stack.c:118 print_irq_inversion_bug kernel/locking/lockdep.c:3429 [inline] check_usage_forwards.cold+0x1e/0x27 kernel/locking/lockdep.c:3453 mark_lock_irq kernel/locking/lockdep.c:3568 [inline] mark_lock+0x54b/0x1710 kernel/locking/lockdep.c:4006 mark_usage kernel/locking/lockdep.c:3902 [inline] __lock_acquire+0x13ad/0x5640 kernel/locking/lockdep.c:4380 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 io_timeout_fn+0x6c/0x3f0 fs/io_uring.c:4999 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1584 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1646 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1079 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1096 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1090 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x4b/0x80 kernel/locking/spinlock.c:199 Code: c0 58 34 b6 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 31 48 83 3d 06 e0 c2 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 bb 6c 5c f9 65 8b 05 54 aa 0e 78 85 c0 74 02 5d RSP: 0018:ffffc900054af8b0 EFLAGS: 00000286 RAX: 1ffffffff136c68b RBX: 0000000000000000 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff87f3542f RBP: ffff8880a6b534c0 R08: 0000000000000001 R09: ffffffff8c5eaadf R10: fffffbfff18bd55b R11: 000000000001f8e0 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880a61c4d00 spin_unlock_irq include/linux/spinlock.h:404 [inline] io_timeout fs/io_uring.c:5162 [inline] io_issue_sqe+0x2de6/0x60d0 fs/io_uring.c:5594 __io_queue_sqe+0x284/0x1190 fs/io_uring.c:5981 io_queue_sqe+0x73e/0x1130 fs/io_uring.c:6060 io_submit_sqe fs/io_uring.c:6130 [inline] io_submit_sqes+0x1794/0x2380 fs/io_uring.c:6327 __do_sys_io_uring_enter+0xdc7/0x1ae0 fs/io_uring.c:8036 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440b99 Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffc41ef4908 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffff