syzbot


INFO: rcu detected stall in sys_fallocate

Status: closed as invalid on 2022/02/08 09:50
Subsystems: ext4
[Documentation on labels]
First crash: 840d, last: 840d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_fallocate (2) ext4 1 607d 607d 0/26 auto-obsoleted due to no activity on 2022/11/24 05:24

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=965/1/0x4000000000000000 softirq=9811/9812 fqs=5 
	(detected by 0, t=10502 jiffies, g=11589, q=228)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4573 Comm: syz-executor.3 Not tainted 5.16.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_preemption_disabled+0x31/0x170 lib/smp_processor_id.c:16
Code: 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 7d 08 be 76 65 8b 1d ee 62 be 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 <85> db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d 41 5c 41 5d 41 5e c3 0f
RSP: 0018:ffffc90000dc0bc8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000010004 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000010004 RDI: 0000000000000000
RBP: ffffffff8a052960 R08: 0000000000000000 R09: ffffffff8d915b17
R10: fffffbfff1b22b62 R11: 0000000000000001 R12: 0000000000000001
R13: ffffffff89ac0f60 R14: 00000000ffffffff R15: ffff88802da261d8
FS:  00007f7aa1a2a700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e526000 CR3: 000000007f6ea000 CR4: 0000000000350ee0
Call Trace:
 <IRQ>
 lockdep_recursion_finish kernel/locking/lockdep.c:438 [inline]
 lock_is_held_type+0xd7/0x140 kernel/locking/lockdep.c:5681
 lock_is_held include/linux/lockdep.h:283 [inline]
 rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x522/0x720 kernel/locking/lockdep.c:5648
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194
 debug_object_activate+0x287/0x3e0 lib/debugobjects.c:689
 debug_hrtimer_activate kernel/time/hrtimer.c:420 [inline]
 debug_activate kernel/time/hrtimer.c:475 [inline]
 enqueue_hrtimer+0x27/0x3e0 kernel/time/hrtimer.c:1084
 __run_hrtimer kernel/time/hrtimer.c:1702 [inline]
 __hrtimer_run_queues+0xb02/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:finish_task_switch.isra.0+0x323/0xb80 kernel/sched/core.c:4852
Code: a3 6a f3 07 85 c0 75 02 0f 0b 48 85 db 0f 85 25 01 00 00 4c 89 f7 e8 fc f7 ff ff e8 87 3c 2d 00 fb 65 48 8b 1c 25 40 70 02 00 <48> 8d bb 80 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc90004896fd8 EFLAGS: 00000202
RAX: 00000000000009b9 RBX: ffff88802da25700 RCX: 1ffffffff1ff740e
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90004897020 R08: 0000000000000001 R09: ffffffff8ff76ab7
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880b9d3a7d8
R13: ffff888022e75700 R14: ffff8880b9d39a80 R15: ffff8880b9d3a4b8
 context_switch kernel/sched/core.c:4975 [inline]
 __schedule+0xaa2/0x4900 kernel/sched/core.c:6253
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6419
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x57/0x70 kernel/locking/spinlock.c:194
 __debug_check_no_obj_freed lib/debugobjects.c:1002 [inline]
 debug_check_no_obj_freed+0x20c/0x420 lib/debugobjects.c:1023
 free_pages_prepare mm/page_alloc.c:1343 [inline]
 free_pcp_prepare+0x2ae/0x870 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3309 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3388
 __stack_depot_save+0x16d/0x4f0 lib/stackdepot.c:391
 kasan_save_stack+0x38/0x50 mm/kasan/common.c:40
 kasan_set_track+0x21/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free mm/kasan/common.c:328 [inline]
 __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1723 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1749
 slab_free mm/slub.c:3513 [inline]
 kmem_cache_free+0xbd/0x5d0 mm/slub.c:3530
 ext4_put_io_end_defer fs/ext4/page-io.c:292 [inline]
 ext4_put_io_end_defer+0x304/0x450 fs/ext4/page-io.c:287
 ext4_writepages+0x94c/0x3b90 fs/ext4/inode.c:2754
 do_writepages+0x1ab/0x690 mm/page-writeback.c:2364
 filemap_fdatawrite_wbc mm/filemap.c:407 [inline]
 filemap_fdatawrite_wbc+0x143/0x1b0 mm/filemap.c:397
 __filemap_fdatawrite_range mm/filemap.c:440 [inline]
 filemap_write_and_wait_range mm/filemap.c:718 [inline]
 filemap_write_and_wait_range+0xe1/0x1a0 mm/filemap.c:712
 ext4_punch_hole+0x1ff/0x1110 fs/ext4/inode.c:3959
 ext4_fallocate+0x1169/0x41d0 fs/ext4/extents.c:4703
 vfs_fallocate+0x48d/0xe10 fs/open.c:307
 ksys_fallocate fs/open.c:330 [inline]
 __do_sys_fallocate fs/open.c:338 [inline]
 __se_sys_fallocate fs/open.c:336 [inline]
 __x64_sys_fallocate+0xcf/0x140 fs/open.c:336
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f7aa30b4e99
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:00007f7aa1a2a168 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f7aa31c7f60 RCX: 00007f7aa30b4e99
RDX: 0000000000800000 RSI: 0000000100000003 RDI: 0000000000000004
RBP: 00007f7aa310eff1 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000080019c R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe82ca8bff R14: 00007f7aa1a2a300 R15: 0000000000022000
 </TASK>
rcu: rcu_preempt kthread starved for 10492 jiffies! g11589 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:28680 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4972 [inline]
 __schedule+0xa9a/0x4900 kernel/sched/core.c:6253
 schedule+0xd2/0x260 kernel/sched/core.c:6326
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 3944 Comm: kworker/u4:8 Not tainted 5.16.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound toggle_allocation_gate
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_check_gp_kthread_starvation.cold+0x1fb/0x200 kernel/rcu/tree_stall.h:481
 print_other_cpu_stall kernel/rcu/tree_stall.h:586 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:729 [inline]
 rcu_pending kernel/rcu/tree.c:3878 [inline]
 rcu_sched_clock_irq+0x1f7c/0x2150 kernel/rcu/tree.c:2597
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0x452/0xc20 kernel/smp.c:969
Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 70 74 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 33 06 00 00 8b 43 08 31
RSP: 0018:ffffc9000579f9f8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b9d3fca0 RCX: 0000000000000000
RDX: ffff88801e6a3a00 RSI: ffffffff816c1dc0 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff816c1de6 R11: 0000000000000000 R12: ffffed10173a7f95
R13: 0000000000000001 R14: ffff8880b9d3fca8 R15: 0000000000000001
 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1135
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1112 [inline]
 text_poke_bp_batch+0x1b3/0x560 arch/x86/kernel/alternative.c:1297
 text_poke_flush arch/x86/kernel/alternative.c:1451 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:1448 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1458
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x1da/0x400 kernel/jump_label.c:830
 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate mm/kfence/core.c:733 [inline]
 toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:725
 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298
 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
----------------
Code disassembly (best guess):
   0:	41 54                	push   %r12
   2:	55                   	push   %rbp
   3:	48 89 fd             	mov    %rdi,%rbp
   6:	53                   	push   %rbx
   7:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   c:	65 44 8b 25 7d 08 be 	mov    %gs:0x76be087d(%rip),%r12d        # 0x76be0891
  13:	76
  14:	65 8b 1d ee 62 be 76 	mov    %gs:0x76be62ee(%rip),%ebx        # 0x76be6309
  1b:	81 e3 ff ff ff 7f    	and    $0x7fffffff,%ebx
  21:	31 ff                	xor    %edi,%edi
  23:	89 de                	mov    %ebx,%esi
  25:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
* 2a:	85 db                	test   %ebx,%ebx <-- trapping instruction
  2c:	74 11                	je     0x3f
  2e:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  33:	44 89 e0             	mov    %r12d,%eax
  36:	5b                   	pop    %rbx
  37:	5d                   	pop    %rbp
  38:	41 5c                	pop    %r12
  3a:	41 5d                	pop    %r13
  3c:	41 5e                	pop    %r14
  3e:	c3                   	retq
  3f:	0f                   	.byte 0xf

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/01/05 19:35 upstream c9e6606c7fe9 6acc789a .config console log report info ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_fallocate
* Struck through repros no longer work on HEAD.