syzbot


INFO: rcu detected stall in vfs_fallocate

Status: auto-closed as invalid on 2021/12/01 16:15
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 484d, last: 456d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: rcu detected stall in vfs_fallocate 1 133d 133d 0/1 auto-obsoleted due to no activity on 2022/11/19 13:27
upstream INFO: rcu detected stall in vfs_fallocate (2) 1 327d 327d 0/24 closed as invalid on 2022/02/08 10:00
linux-4.19 BUG: soft lockup in vfs_fallocate 1 565d 565d 0/1 auto-closed as invalid on 2021/09/13 17:50

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=aaa/1/0x4000000000000000 softirq=147065/147065 fqs=0 
	(t=10501 jiffies g=283869 q=53)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g283869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=114662
rcu: rcu_preempt kthread starved for 10504 jiffies! g283869 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:I stack:28864 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4681 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5938
 schedule+0xd3/0x270 kernel/sched/core.c:6017
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop kernel/rcu/tree.c:1996 [inline]
 rcu_gp_kthread+0xd34/0x1980 kernel/rcu/tree.c:2169
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 1239 Comm: syz-executor.5 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 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+0x1d1/0x1d6 kernel/rcu/tree_stall.h:479
 print_cpu_stall kernel/rcu/tree_stall.h:623 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:700 [inline]
 rcu_pending kernel/rcu/tree.c:3922 [inline]
 rcu_sched_clock_irq.cold+0x9a/0x747 kernel/rcu/tree.c:2641
 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:1421
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x3ba/0xb40 kernel/locking/qspinlock.c:508
Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f
RSP: 0018:ffffc90002f96fe8 EFLAGS: 00000206
RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffff11028f74070
RDX: 0000000000000001 RSI: ffffffff817bd241 RDI: ffffffff81332591
RBP: ffff888147ba0380 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817bd209 R11: 0000000000000000 R12: 00000000000015de
R13: ffffed1028f74070 R14: 0000000000000001 R15: ffff8880b9d52900
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
 spin_lock include/linux/spinlock.h:354 [inline]
 ext4_lock_group+0x1e5/0x240 fs/ext4/ext4.h:3456
 ext4_mb_find_by_goal+0x2ca/0xd60 fs/ext4/mballoc.c:2215
 ext4_mb_regular_allocator+0x237/0x3870 fs/ext4/mballoc.c:2636
 ext4_mb_new_blocks+0x24d4/0x5230 fs/ext4/mballoc.c:5515
 ext4_ext_map_blocks+0x1fa3/0x6070 fs/ext4/extents.c:4245
 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:638
 ext4_alloc_file_blocks.isra.0+0x2c1/0xae0 fs/ext4/extents.c:4432
 ext4_fallocate+0x45e/0x3ff0 fs/ext4/extents.c:4712
 vfs_fallocate+0x48d/0xd80 fs/open.c:311
 ioctl_preallocate+0x18e/0x200 fs/ioctl.c:497
 file_ioctl fs/ioctl.c:537 [inline]
 do_vfs_ioctl+0x1144/0x15d0 fs/ioctl.c:1048
 __do_sys_ioctl fs/ioctl.c:1067 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x108/0x200 fs/ioctl.c:1055
 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: 0033:0x4665f9
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:00007f4ded5a5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9
RDX: 0000000020000040 RSI: 000000004030582a RDI: 0000000000000005
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038
R13: 00007ffc1f26ae4f R14: 00007f4ded5a5300 R15: 0000000000022000
NMI backtrace for cpu 1
CPU: 1 PID: 1239 Comm: syz-executor.5 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:342
 print_cpu_stall kernel/rcu/tree_stall.h:625 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:700 [inline]
 rcu_pending kernel/rcu/tree.c:3922 [inline]
 rcu_sched_clock_irq.cold+0x9f/0x747 kernel/rcu/tree.c:2641
 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:1421
 __run_hrtimer kernel/time/hrtimer.c:1537 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1601
 hrtimer_interrupt+0x330/0xa00 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x3ba/0xb40 kernel/locking/qspinlock.c:508
Code: eb c6 45 01 01 41 bc 00 80 00 00 48 c1 e9 03 83 e3 07 41 be 01 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 8d 2c 01 eb 0c f3 90 <41> 83 ec 01 0f 84 72 04 00 00 41 0f b6 45 00 38 d8 7f 08 84 c0 0f
RSP: 0018:ffffc90002f96fe8 EFLAGS: 00000206
RAX: 0000000000000003 RBX: 0000000000000000 RCX: 1ffff11028f74070
RDX: 0000000000000001 RSI: ffffffff817bd241 RDI: ffffffff81332591
RBP: ffff888147ba0380 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817bd209 R11: 0000000000000000 R12: 00000000000015de
R13: ffffed1028f74070 R14: 0000000000000001 R15: ffff8880b9d52900
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x200/0x2b0 kernel/locking/spinlock_debug.c:113
 spin_lock include/linux/spinlock.h:354 [inline]
 ext4_lock_group+0x1e5/0x240 fs/ext4/ext4.h:3456
 ext4_mb_find_by_goal+0x2ca/0xd60 fs/ext4/mballoc.c:2215
 ext4_mb_regular_allocator+0x237/0x3870 fs/ext4/mballoc.c:2636
 ext4_mb_new_blocks+0x24d4/0x5230 fs/ext4/mballoc.c:5515
 ext4_ext_map_blocks+0x1fa3/0x6070 fs/ext4/extents.c:4245
 ext4_map_blocks+0x653/0x17d0 fs/ext4/inode.c:638
 ext4_alloc_file_blocks.isra.0+0x2c1/0xae0 fs/ext4/extents.c:4432
 ext4_fallocate+0x45e/0x3ff0 fs/ext4/extents.c:4712
 vfs_fallocate+0x48d/0xd80 fs/open.c:311
 ioctl_preallocate+0x18e/0x200 fs/ioctl.c:497
 file_ioctl fs/ioctl.c:537 [inline]
 do_vfs_ioctl+0x1144/0x15d0 fs/ioctl.c:1048
 __do_sys_ioctl fs/ioctl.c:1067 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x108/0x200 fs/ioctl.c:1055
 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: 0033:0x4665f9
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:00007f4ded5a5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9
RDX: 0000000020000040 RSI: 000000004030582a RDI: 0000000000000005
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038
R13: 00007ffc1f26ae4f R14: 00007f4ded5a5300 R15: 0000000000022000
----------------
Code disassembly (best guess):
   0:	eb c6                	jmp    0xffffffc8
   2:	45 01 01             	add    %r8d,(%r9)
   5:	41 bc 00 80 00 00    	mov    $0x8000,%r12d
   b:	48 c1 e9 03          	shr    $0x3,%rcx
   f:	83 e3 07             	and    $0x7,%ebx
  12:	41 be 01 00 00 00    	mov    $0x1,%r14d
  18:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1f:	fc ff df
  22:	4c 8d 2c 01          	lea    (%rcx,%rax,1),%r13
  26:	eb 0c                	jmp    0x34
  28:	f3 90                	pause
* 2a:	41 83 ec 01          	sub    $0x1,%r12d <-- trapping instruction
  2e:	0f 84 72 04 00 00    	je     0x4a6
  34:	41 0f b6 45 00       	movzbl 0x0(%r13),%eax
  39:	38 d8                	cmp    %bl,%al
  3b:	7f 08                	jg     0x45
  3d:	84 c0                	test   %al,%al
  3f:	0f                   	.byte 0xf

Crashes (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-bpf-kasan-gce 2021/09/02 16:06 bpf 57f780f1c433 15cea0a3 .config log report info INFO: rcu detected stall in vfs_fallocate
ci-upstream-bpf-kasan-gce 2021/08/28 18:36 bpf 5b029a32cfe4 be2c130d .config log report info INFO: rcu detected stall in vfs_fallocate
ci-upstream-bpf-kasan-gce 2021/08/05 20:24 bpf a02215ce72a3 d2d6e680 .config log report info INFO: rcu detected stall in vfs_fallocate
ci-upstream-bpf-next-kasan-gce 2021/08/30 23:21 bpf-next fca35b11e18a 8f58a0ef .config log report info INFO: rcu detected stall in vfs_fallocate
ci-upstream-bpf-next-kasan-gce 2021/08/28 14:17 bpf-next 47bb27a20d6e be2c130d .config log report info INFO: rcu detected stall in vfs_fallocate
ci-upstream-bpf-kasan-gce 2021/08/30 15:53 bpf 57f780f1c433 8f58a0ef .config log report info BUG: soft lockup in vfs_fallocate
* Struck through repros no longer work on HEAD.