======================================================== WARNING: possible irq lock inversion dependency detected 6.4.0-rc7-next-20230623 #1 Not tainted -------------------------------------------------------- syz-executor.5/274 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.5/274: #0: ffffffff856c2c40 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_node+0x4b/0x3b0 #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 __mutex_lock+0x12a/0x1a30 __flush_workqueue+0x137/0x1110 cgroup_procs_write_finish+0xeb/0x170 __cgroup_procs_write+0x371/0x6b0 cgroup_procs_write+0x26/0x60 cgroup_file_write+0x1e5/0x7c0 kernfs_fop_write_iter+0x3f7/0x610 vfs_write+0x97d/0xda0 ksys_write+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 __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 lock_acquire+0x1c7/0x4c0 _raw_spin_lock+0x2b/0x40 d_walk+0x10d/0x910 shrink_dcache_parent+0x98/0x400 vfs_rmdir.part.0+0x27c/0x5b0 do_rmdir+0x33e/0x400 __x64_sys_rmdir+0xca/0x110 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_workfn+0x486/0xed0 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+0x8c8/0x28b0 __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 fs_reclaim_acquire+0x121/0x170 kmem_cache_alloc_node+0x4b/0x3b0 copy_process+0x3c2/0x7320 kernel_clone+0xeb/0x7d0 __do_sys_clone+0xba/0x100 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 fs_reclaim_acquire+0x121/0x170 kmem_cache_alloc_node+0x4b/0x3b0 copy_process+0x3c2/0x7320 kernel_clone+0xeb/0x7d0 __do_sys_clone+0xba/0x100 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 mem_cgroup_wb_stats+0x3d8/0x4b0 wb_over_bg_thresh+0x30e/0x6a0 wb_workfn+0x486/0xed0 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+0x8c8/0x28b0 __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 fs_reclaim_acquire+0x121/0x170 kmem_cache_alloc_node+0x4b/0x3b0 copy_process+0x3c2/0x7320 kernel_clone+0xeb/0x7d0 __do_sys_clone+0xba/0x100 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 stack backtrace: CPU: 0 PID: 274 Comm: syz-executor.5 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:ffff888016f579f0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff11002deaf40 RCX: 0000000000000001 RDX: 1ffff11002b304a5 RSI: 0000000000000008 RDI: ffffffff8715c6b8 RBP: 0000000000000001 R08: 0000000000000000 R09: fffffbfff0ef9b62 R10: ffffffff877cdb17 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff856c2c40 R15: 0000000000000000 fs_reclaim_acquire+0x121/0x170 kmem_cache_alloc_node+0x4b/0x3b0 copy_process+0x3c2/0x7320 kernel_clone+0xeb/0x7d0 __do_sys_clone+0xba/0x100 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f1b6e27410b Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007fff1eb48bd0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1b6e27410b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000555557123400 R10: 00005555571236d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007fff1eb48cb0 loop3: detected capacity change from 0 to 512 EXT4-fs error (device loop3): __ext4_fill_super:5467: inode #2: comm syz-executor.3: iget: special inode unallocated EXT4-fs (loop3): get root inode failed EXT4-fs (loop3): mount failed FAULT_INJECTION: forcing a failure. name fail_usercopy, interval 1, probability 0, space 0, times 0 CPU: 1 PID: 9039 Comm: syz-executor.4 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+0xc1/0xf0 should_fail_ex+0x4b4/0x5b0 _copy_from_iter+0x1d3/0x1320 netlink_sendmsg+0x880/0xe40 sock_sendmsg+0x1b6/0x200 ____sys_sendmsg+0x76a/0x9a0 ___sys_sendmsg+0x110/0x1b0 __sys_sendmsg+0xf7/0x1d0 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f248de0eb19 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:00007f248b384188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f248df21f60 RCX: 00007f248de0eb19 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007f248b3841d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd084480ef R14: 00007f248b384300 R15: 0000000000022000 loop3: detected capacity change from 0 to 512 EXT4-fs (loop3): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. EXT4-fs (loop3): unmounting filesystem 00000000-0000-0000-0000-000000000000. ---------------- 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