mmap: syz-executor.0 (5640) uses deprecated remap_file_pages() syscall. See Documentation/mm/remap_file_pages.rst. ======================================================== WARNING: possible irq lock inversion dependency detected 6.4.0-rc7-next-20230623 #1 Not tainted -------------------------------------------------------- syz-executor.2/5651 just changed the state of lock: ffffffff85815818 (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 *** 3 locks held by syz-executor.2/5651: #0: ffff888019af4ba0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x1ae/0x8d0 #1: ffffffff8560b5a0 (rcu_callback){....}-{0:0}, at: rcu_core+0x83e/0x28b0 #2: 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 lock_acquire+0x1c7/0x4c0 __task_pid_nr_ns+0x41/0x4f0 cgroup_procs_show+0x1e/0x40 cgroup_seqfile_show+0x1ad/0x310 seq_read_iter+0xbe2/0x1300 kernfs_fop_read_iter+0x4d4/0x690 vfs_read+0x4b5/0x8f0 ksys_read+0x122/0x250 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_state+0x86/0x160 memcg_account_kmem+0x38/0x70 refill_obj_stock+0x35f/0x5c0 kmem_cache_free+0x444/0x4d0 rcu_core+0x8c8/0x28b0 __do_softirq+0x1b7/0x7d4 run_ksoftirqd+0x29/0x50 smpboot_thread_fn+0x40b/0x930 kthread+0x33f/0x440 ret_from_fork+0x2c/0x50 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 flush_memcg_stats_dwork+0x9/0x50 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+0x8c8/0x28b0 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 lock_acquire+0x136/0x4c0 percpu_ref_put_many.constprop.0+0x29/0x110 kmem_cache_free+0x47c/0x4d0 remove_vma+0x123/0x170 exit_mmap+0x332/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2740 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+0x8c8/0x28b0 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 lock_acquire+0x136/0x4c0 percpu_ref_put_many.constprop.0+0x29/0x110 kmem_cache_free+0x47c/0x4d0 remove_vma+0x123/0x170 exit_mmap+0x332/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2740 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 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: [] 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+0x8c8/0x28b0 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 lock_acquire+0x136/0x4c0 percpu_ref_put_many.constprop.0+0x29/0x110 kmem_cache_free+0x47c/0x4d0 remove_vma+0x123/0x170 exit_mmap+0x332/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2740 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: 5651 Comm: syz-executor.2 Not tainted 6.4.0-rc7-next-20230623 #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+0x8c8/0x28b0 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:lock_acquire+0x136/0x4c0 Code: 85 f5 00 00 00 65 48 8b 14 25 c0 8a 03 00 48 8d ba ec 09 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 0f b6 0c 01 <48> 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 20 03 00 00 8b RSP: 0018:ffff888040fbf8d0 EFLAGS: 00000213 RAX: dffffc0000000000 RBX: 1ffff110081f7f1c RCX: 0000000000000000 RDX: ffff8880169c51c0 RSI: 0000000000000008 RDI: ffff8880169c5bac RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff0ba8122 R10: ffffffff85d40917 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8560b6c0 R15: 0000000000000000 percpu_ref_put_many.constprop.0+0x29/0x110 kmem_cache_free+0x47c/0x4d0 remove_vma+0x123/0x170 exit_mmap+0x332/0x8d0 mmput+0xd5/0x390 do_exit+0x99f/0x2740 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: 0033:0x7fe142a83b19 Code: Unable to access opcode bytes at 0x7fe142a83aef. RSP: 002b:00007fe13ff96218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fe142b971a8 RCX: 00007fe142a83b19 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fe142b971ac RBP: 00007fe142b971a0 R08: 000000000000000e R09: 0000000000000000 R10: 000000000000003e R11: 0000000000000246 R12: 00007fe142b971ac R13: 00007ffd5427609f R14: 00007fe13ff96300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 85 f5 test %esi,%ebp 2: 00 00 add %al,(%rax) 4: 00 65 48 add %ah,0x48(%rbp) 7: 8b 14 25 c0 8a 03 00 mov 0x38ac0,%edx e: 48 8d ba ec 09 00 00 lea 0x9ec(%rdx),%rdi 15: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1c: fc ff df 1f: 48 89 f9 mov %rdi,%rcx 22: 48 c1 e9 03 shr $0x3,%rcx 26: 0f b6 0c 01 movzbl (%rcx,%rax,1),%ecx * 2a: 48 89 f8 mov %rdi,%rax <-- trapping instruction 2d: 83 e0 07 and $0x7,%eax 30: 83 c0 03 add $0x3,%eax 33: 38 c8 cmp %cl,%al 35: 7c 08 jl 0x3f 37: 84 c9 test %cl,%cl 39: 0f 85 20 03 00 00 jne 0x35f 3f: 8b .byte 0x8b