======================================================== WARNING: possible irq lock inversion dependency detected 6.4.0-rc7-next-20230623 #1 Not tainted -------------------------------------------------------- syz-executor.2/5606 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 *** 4 locks held by syz-executor.2/5606: #0: ffff88800bbfe3e8 (sb_writers#3){.+.+}-{0:0}, at: __ext4_ioctl+0x290a/0x3d40 #1: ffffffff8560b6c0 (rcu_read_lock){....}-{1:2}, at: __is_insn_slot_addr+0x4/0x290 #2: ffffffff8560b5a0 (rcu_callback){....}-{0:0}, at: rcu_core+0x83e/0x28b0 #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 _raw_spin_unlock_irqrestore+0x34/0x50 kmem_cache_alloc_lru+0x2e7/0x680 __d_alloc+0x31/0x9c0 d_alloc_parallel+0x10e/0x1640 lookup_open.isra.0+0x909/0x1400 path_openat+0x96c/0x2710 do_filp_open+0x1ba/0x410 do_sys_openat2+0x164/0x1d0 __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 __cgroup_account_cputime+0x75/0xc0 update_curr+0x350/0x6d0 dequeue_task_fair+0x20e/0x14a0 load_balance+0xcb4/0x2790 rebalance_domains+0x66c/0xc00 __do_softirq+0x1b7/0x7d4 irq_exit_rcu+0x93/0xc0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x1a/0x20 default_idle+0xf/0x20 default_idle_call+0x67/0xa0 do_idle+0x305/0x3c0 cpu_startup_entry+0x18/0x20 start_secondary+0x1ba/0x210 secondary_startup_64_no_verify+0x179/0x17b 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+0x1c7/0x4c0 __is_insn_slot_addr+0x41/0x290 kernel_text_address+0x5b/0xc0 __kernel_text_address+0xd/0x40 unwind_get_return_address+0x59/0xa0 arch_stack_walk+0x9d/0xf0 stack_trace_save+0x90/0xd0 kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc+0x16b/0x370 mempool_alloc+0x15a/0x370 bio_alloc_bioset+0x41a/0x8d0 submit_bh_wbc+0x281/0x5c0 __sync_dirty_buffer+0x174/0x380 ext4_update_superblocks_fn+0xb39/0x1190 __ext4_ioctl+0x293d/0x3d40 __x64_sys_ioctl+0x1a4/0x210 do_syscall_64+0x3f/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+0x1c7/0x4c0 __is_insn_slot_addr+0x41/0x290 kernel_text_address+0x5b/0xc0 __kernel_text_address+0xd/0x40 unwind_get_return_address+0x59/0xa0 arch_stack_walk+0x9d/0xf0 stack_trace_save+0x90/0xd0 kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc+0x16b/0x370 mempool_alloc+0x15a/0x370 bio_alloc_bioset+0x41a/0x8d0 submit_bh_wbc+0x281/0x5c0 __sync_dirty_buffer+0x174/0x380 ext4_update_superblocks_fn+0xb39/0x1190 __ext4_ioctl+0x293d/0x3d40 __x64_sys_ioctl+0x1a4/0x210 do_syscall_64+0x3f/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+0x1c7/0x4c0 __is_insn_slot_addr+0x41/0x290 kernel_text_address+0x5b/0xc0 __kernel_text_address+0xd/0x40 unwind_get_return_address+0x59/0xa0 arch_stack_walk+0x9d/0xf0 stack_trace_save+0x90/0xd0 kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc+0x16b/0x370 mempool_alloc+0x15a/0x370 bio_alloc_bioset+0x41a/0x8d0 submit_bh_wbc+0x281/0x5c0 __sync_dirty_buffer+0x174/0x380 ext4_update_superblocks_fn+0xb39/0x1190 __ext4_ioctl+0x293d/0x3d40 __x64_sys_ioctl+0x1a4/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 stack backtrace: CPU: 0 PID: 5606 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+0x1c7/0x4c0 Code: ff ff 48 83 c4 28 65 0f c1 05 a5 bb d4 7e 83 f8 01 0f 85 8f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffff8880420b73a8 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff11008416e77 RCX: 0000000000000001 RDX: 1ffff11007b4713d RSI: bdb34cbc52517cd0 RDI: 00000000f00d25a2 RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff0ef9b60 R10: ffffffff877cdb07 R11: 0000000000000001 R12: 0000000000000002 R13: 0000000000000000 R14: ffffffff8560b6c0 R15: 0000000000000000 __is_insn_slot_addr+0x41/0x290 kernel_text_address+0x5b/0xc0 __kernel_text_address+0xd/0x40 unwind_get_return_address+0x59/0xa0 arch_stack_walk+0x9d/0xf0 stack_trace_save+0x90/0xd0 kasan_save_stack+0x22/0x50 kasan_set_track+0x25/0x30 __kasan_slab_alloc+0x59/0x70 kmem_cache_alloc+0x16b/0x370 mempool_alloc+0x15a/0x370 bio_alloc_bioset+0x41a/0x8d0 submit_bh_wbc+0x281/0x5c0 __sync_dirty_buffer+0x174/0x380 ext4_update_superblocks_fn+0xb39/0x1190 __ext4_ioctl+0x293d/0x3d40 __x64_sys_ioctl+0x1a4/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f8cc3475b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8cc09eb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f8cc3588f60 RCX: 00007f8cc3475b19 RDX: 0000000020000180 RSI: 0000000041009432 RDI: 0000000000000005 RBP: 00007f8cc34cff6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce5e5200f R14: 00007f8cc09eb300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 48 83 c4 28 add $0x28,%rsp 4: 65 0f c1 05 a5 bb d4 xadd %eax,%gs:0x7ed4bba5(%rip) # 0x7ed4bbb1 b: 7e c: 83 f8 01 cmp $0x1,%eax f: 0f 85 8f 02 00 00 jne 0x2a4 15: 48 83 7c 24 08 00 cmpq $0x0,0x8(%rsp) 1b: 74 01 je 0x1e 1d: fb sti 1e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 25: fc ff df * 28: 48 01 c3 add %rax,%rbx <-- trapping instruction 2b: 48 c7 03 00 00 00 00 movq $0x0,(%rbx) 32: 48 c7 43 08 00 00 00 movq $0x0,0x8(%rbx) 39: 00 3a: 48 rex.W 3b: 8b .byte 0x8b 3c: 84 .byte 0x84 3d: 24 .byte 0x24