======================================================== WARNING: possible irq lock inversion dependency detected 6.4.0-rc7-next-20230622 #1 Not tainted -------------------------------------------------------- syz-executor.4/31732 just changed the state of lock: ffffffff85814c18 (blkg_stat_lock){+.-.}-{2:2}, at: __blkcg_rstat_flush.isra.0+0x11f/0x4e0 but this lock was taken by another, HARDIRQ-safe lock in the past: (per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)){-.-.}-{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(blkg_stat_lock); local_irq_disable(); lock(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)); lock(blkg_stat_lock); lock(per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)); *** DEADLOCK *** 4 locks held by syz-executor.4/31732: #0: ffff88803e8d54e0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0xf6/0x8d0 #1: ffff888042a44a38 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: __pte_offset_map_lock+0x121/0x290 #2: ffffffff8560b5a0 (rcu_callback){....}-{0:0}, at: rcu_core+0x83e/0x2860 #3: ffffffff8560b6c0 (rcu_read_lock){....}-{1:2}, at: __blkcg_rstat_flush.isra.0+0x93/0x4e0 the shortest dependencies between 2nd lock and 1st lock: -> (per_cpu_ptr(&cgroup_rstat_cpu_lock, cpu)){-.-.}-{2:2} { IN-HARDIRQ-W at: lock_acquire+0x19a/0x4c0 _raw_spin_lock_irqsave+0x3a/0x60 cgroup_rstat_updated+0xcb/0x2e0 __cgroup_account_cputime_field+0xa0/0x120 account_system_index_time+0x199/0x2c0 update_process_times+0x26/0x150 tick_sched_handle+0x8e/0x170 tick_sched_timer+0xe6/0x110 __hrtimer_run_queues+0x17f/0xb60 hrtimer_interrupt+0x2ef/0x750 __sysvec_apic_timer_interrupt+0xff/0x380 sysvec_apic_timer_interrupt+0x69/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 __sanitizer_cov_trace_pc+0x0/0x70 __check_object_size+0x41f/0x8c0 strncpy_from_user+0xb4/0x340 getname_flags.part.0+0x95/0x4f0 getname+0x92/0xe0 do_sys_openat2+0xec/0x1d0 __x64_sys_openat+0x143/0x200 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 IN-SOFTIRQ-W at: lock_acquire+0x19a/0x4c0 _raw_spin_lock_irqsave+0x3a/0x60 cgroup_rstat_updated+0xcb/0x2e0 __mod_memcg_lruvec_state+0x18d/0x2b0 mod_objcg_mlstate+0x119/0x230 drain_obj_stock+0x125/0x580 refill_obj_stock+0x12d/0x5c0 kmem_cache_free+0x444/0x4d0 rcu_core+0x8c8/0x2860 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 obj_cgroup_charge+0x1a0/0x530 kmem_cache_alloc+0x9f/0x370 vm_area_alloc+0x20/0x200 mmap_region+0x430/0x26c0 do_mmap+0x833/0xea0 vm_mmap_pgoff+0x1a8/0x3b0 ksys_mmap_pgoff+0x3af/0x500 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 INITIAL USE at: lock_acquire+0x19a/0x4c0 _raw_spin_lock_irqsave+0x3a/0x60 cgroup_rstat_flush_locked+0x131/0xd80 cgroup_rstat_flush+0x37/0x50 do_flush_stats+0x97/0xf0 flush_memcg_stats_dwork+0x9/0x50 process_one_work+0xabf/0x1770 worker_thread+0x64f/0x12a0 kthread+0x33f/0x440 ret_from_fork+0x2c/0x50 } ... key at: [] __key.0+0x0/0x40 ... acquired at: _raw_spin_lock+0x2b/0x40 __blkcg_rstat_flush.isra.0+0x11f/0x4e0 blkcg_rstat_flush+0x87/0xb0 cgroup_rstat_flush_locked+0x706/0xd80 cgroup_rstat_flush+0x37/0x50 do_flush_stats+0x97/0xf0 mem_cgroup_wb_stats+0x3d8/0x4b0 wb_over_bg_thresh+0x30e/0x6a0 wb_writeback+0x338/0x980 wb_workfn+0x81d/0xed0 process_one_work+0xabf/0x1770 worker_thread+0x64f/0x12a0 kthread+0x33f/0x440 ret_from_fork+0x2c/0x50 -> (blkg_stat_lock){+.-.}-{2:2} { HARDIRQ-ON-W at: lock_acquire+0x19a/0x4c0 _raw_spin_lock+0x2b/0x40 __blkcg_rstat_flush.isra.0+0x11f/0x4e0 __blkg_release+0xfa/0x3b0 rcu_core+0x8c8/0x2860 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 __sanitizer_cov_trace_const_cmp4+0x8/0x20 unmap_page_range+0xd39/0x2860 unmap_single_vma+0x19a/0x2b0 unmap_vmas+0x233/0x390 exit_mmap+0x16a/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2780 do_group_exit+0xd4/0x2a0 get_signal+0x263f/0x26c0 arch_do_signal_or_restart+0x79/0x590 exit_to_user_mode_prepare+0xeb/0x180 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 IN-SOFTIRQ-W at: lock_acquire+0x19a/0x4c0 _raw_spin_lock+0x2b/0x40 __blkcg_rstat_flush.isra.0+0x11f/0x4e0 __blkg_release+0xfa/0x3b0 rcu_core+0x8c8/0x2860 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 __sanitizer_cov_trace_const_cmp4+0x8/0x20 unmap_page_range+0xd39/0x2860 unmap_single_vma+0x19a/0x2b0 unmap_vmas+0x233/0x390 exit_mmap+0x16a/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2780 do_group_exit+0xd4/0x2a0 get_signal+0x263f/0x26c0 arch_do_signal_or_restart+0x79/0x590 exit_to_user_mode_prepare+0xeb/0x180 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 INITIAL USE at: lock_acquire+0x19a/0x4c0 _raw_spin_lock+0x2b/0x40 __blkcg_rstat_flush.isra.0+0x11f/0x4e0 blkcg_rstat_flush+0x87/0xb0 cgroup_rstat_flush_locked+0x706/0xd80 cgroup_rstat_flush+0x37/0x50 do_flush_stats+0x97/0xf0 mem_cgroup_wb_stats+0x3d8/0x4b0 wb_over_bg_thresh+0x30e/0x6a0 wb_writeback+0x338/0x980 wb_workfn+0x81d/0xed0 process_one_work+0xabf/0x1770 worker_thread+0x64f/0x12a0 kthread+0x33f/0x440 ret_from_fork+0x2c/0x50 } ... key at: [] blkg_stat_lock+0x18/0x60 ... acquired at: __lock_acquire+0x8b8/0x6340 lock_acquire+0x19a/0x4c0 _raw_spin_lock+0x2b/0x40 __blkcg_rstat_flush.isra.0+0x11f/0x4e0 __blkg_release+0xfa/0x3b0 rcu_core+0x8c8/0x2860 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 __sanitizer_cov_trace_const_cmp4+0x8/0x20 unmap_page_range+0xd39/0x2860 unmap_single_vma+0x19a/0x2b0 unmap_vmas+0x233/0x390 exit_mmap+0x16a/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2780 do_group_exit+0xd4/0x2a0 get_signal+0x263f/0x26c0 arch_do_signal_or_restart+0x79/0x590 exit_to_user_mode_prepare+0xeb/0x180 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 stack backtrace: CPU: 0 PID: 31732 Comm: syz-executor.4 Not tainted 6.4.0-rc7-next-20230622 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x91/0xf0 print_irq_inversion_bug.part.0+0x3d5/0x570 mark_lock.part.0+0x900/0x2f50 __lock_acquire+0x8b8/0x6340 lock_acquire+0x19a/0x4c0 _raw_spin_lock+0x2b/0x40 __blkcg_rstat_flush.isra.0+0x11f/0x4e0 __blkg_release+0xfa/0x3b0 rcu_core+0x8c8/0x2860 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x20 Code: bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 2a fe ff ff 66 2e 0f 1f 84 00 00 00 RSP: 0018:ffff888019f876d8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0000ab9600 RCX: ffffffff8170d7a9 RDX: ffff8880354b1b40 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 00007f7fd3f6b000 R14: ffff88800ba63b50 R15: dffffc0000000000 unmap_page_range+0xd39/0x2860 unmap_single_vma+0x19a/0x2b0 unmap_vmas+0x233/0x390 exit_mmap+0x16a/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2780 do_group_exit+0xd4/0x2a0 get_signal+0x263f/0x26c0 arch_do_signal_or_restart+0x79/0x590 exit_to_user_mode_prepare+0xeb/0x180 syscall_exit_to_user_mode+0x1d/0x50 do_syscall_64+0x4c/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f7fd4418b19 Code: Unable to access opcode bytes at 0x7f7fd4418aef. RSP: 002b:00007f7fd194c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f7fd452c0e0 RCX: 00007f7fd4418b19 RDX: 0000000000000007 RSI: 0000000000004c81 RDI: 000000000000000a RBP: 00007f7fd4472f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff09b22bff R14: 00007f7fd194c300 R15: 0000000000022000 tmpfs: Bad value for 'mpol' ---------------- Code disassembly (best guess): 0: bf 03 00 00 00 mov $0x3,%edi 5: e9 58 fe ff ff jmpq 0xfffffe62 a: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 11: 00 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: f3 0f 1e fa endbr64 26: 48 8b 0c 24 mov (%rsp),%rcx * 2a: 89 f2 mov %esi,%edx <-- trapping instruction 2c: 89 fe mov %edi,%esi 2e: bf 05 00 00 00 mov $0x5,%edi 33: e9 2a fe ff ff jmpq 0xfffffe62 38: 66 data16 39: 2e cs 3a: 0f .byte 0xf 3b: 1f (bad) 3c: 84 00 test %al,(%rax)