syzbot


INFO: rcu detected stall in vfs_write

Status: closed as invalid on 2022/02/08 10:00
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 316d, last: 316d

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10499 ticks this GP) idle=ebf/1/0x4000000000000000 softirq=22024/22024 fqs=2 
	(t=10500 jiffies g=30517 q=17)
rcu: rcu_preempt kthread starved for 10496 jiffies! g30517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26576 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4986 [inline]
 __schedule+0x971/0x10e0 kernel/sched/core.c:6296
 schedule+0x12b/0x1f0 kernel/sched/core.c:6369
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x1fd/0x770 kernel/rcu/tree.c:1963
 rcu_gp_kthread+0xa5/0x350 kernel/rcu/tree.c:2136
 kthread+0x468/0x490 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7559 Comm: syz-executor.5 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:check_preemption_disabled+0x7f/0x1c0 lib/smp_processor_id.c:19
Code: 25 28 00 00 00 48 3b 44 24 08 0f 85 52 01 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c <8f> 04 24 4c 8b 24 24 bd 00 02 00 00 be 00 02 00 00 4c 21 e6 31 ff
RSP: 0018:ffffc90000dc0ef0 EFLAGS: 00000046
RAX: 2d38e760671fd900 RBX: 0000000000000001 RCX: 0000000000010000
RDX: 1ffffffff1eeda08 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8f76d040 R09: ffffffff8f76d048
R10: ffffffff8f76d05c R11: ffffffff8f76d050 R12: ffffc90000dc0f80
R13: 0000000000000000 R14: ffffffff8a6d5040 R15: ffffffff8ad5ee60
FS:  00007f91f91b0700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020e00010 CR3: 000000005ff4c000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 invoke_softirq+0x10/0xd0 kernel/softirq.c:422
 __irq_exit_rcu+0xec/0x170 kernel/softirq.c:637
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:memset_erms+0xb/0x10
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffffc90004617cb8 EFLAGS: 00000202
RAX: ffff88801a166000 RBX: ffffc90004617d80 RCX: 0000000000000000
RDX: 0000000000000018 RSI: 0000000000000000 RDI: ffffc90004617d80
RBP: ffffc90004617e50 R08: dffffc0000000000 R09: ffffc90004617d68
R10: fffff520008c2fb0 R11: 0000000000000000 R12: ffffc90004617d60
R13: 0000000000000000 R14: 1ffff920008c2fa4 R15: 0000000000000000
 init_sync_kiocb include/linux/fs.h:2251 [inline]
 new_sync_write fs/read_write.c:499 [inline]
 vfs_write+0x9a2/0xe90 fs/read_write.c:590
 ksys_pwrite64 fs/read_write.c:697 [inline]
 __do_sys_pwrite64 fs/read_write.c:707 [inline]
 __se_sys_pwrite64 fs/read_write.c:704 [inline]
 __x64_sys_pwrite64+0x1b2/0x240 fs/read_write.c:704
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f91fa7edfb7
Code: 08 89 3c 24 48 89 4c 24 18 e8 e5 f8 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 48 8b 74 24 08 8b 3c 24 b8 12 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 04 24 e8 15 f9 ff ff 48 8b
RSP: 002b:00007f91f91aff00 EFLAGS: 00000293 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f91fa8849c8 RCX: 00007f91fa7edfb7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0aaaaaaaaaaaabe2 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005
R13: 0000000000000005 R14: 0000000020edf2c0 R15: 000000000009ea08
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 7551 Comm: syz-executor.2 Not tainted 5.16.0-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+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3919 [inline]
 rcu_sched_clock_irq+0x1e33/0x2bc0 kernel/rcu/tree.c:2617
 update_process_times+0x197/0x200 kernel/time/timer.c:1785
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:lock_release+0x1/0x810 kernel/locking/lockdep.c:5647
Code: e1 07 80 c1 03 38 c1 0f 8c 50 f3 ff ff 48 c7 c7 68 98 00 8e e8 30 0c 6a 00 e9 3f f3 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 55 <48> 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 00 01 00
RSP: 0018:ffffc9000441fc88 EFLAGS: 00000246
RAX: 1ffff110033cd1b8 RBX: ffff888019e68dc0 RCX: 0000000000040000
RDX: ffff88801d3a9d00 RSI: ffffffff81db3410 RDI: ffff8880115cc460
RBP: 0000000000008000 R08: ffffffff81db2a5d R09: ffffed10033cd1d0
R10: ffffed10033cd1d0 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff11005189f80 R14: ffff8880115cc000 R15: dffffc0000000000
 percpu_up_read include/linux/percpu-rwsem.h:99 [inline]
 __sb_end_write include/linux/fs.h:1729 [inline]
 file_end_write+0x97/0x230 include/linux/fs.h:2963
 vfs_write+0x7e0/0xe90 fs/read_write.c:598
 ksys_pwrite64 fs/read_write.c:697 [inline]
 __do_sys_pwrite64 fs/read_write.c:707 [inline]
 __se_sys_pwrite64 fs/read_write.c:704 [inline]
 __x64_sys_pwrite64+0x1b2/0x240 fs/read_write.c:704
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa4a8848fb7
Code: 08 89 3c 24 48 89 4c 24 18 e8 e5 f8 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 48 8b 74 24 08 8b 3c 24 b8 12 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 04 24 e8 15 f9 ff ff 48 8b
RSP: 002b:00007fa4a720af00 EFLAGS: 00000293 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fa4a88df9c8 RCX: 00007fa4a8848fb7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0aaaaaaaaaaaabe2 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005
R13: 0000000000000005 R14: 0000000020b5e6e0 R15: 0000000000079434
 </TASK>
sched: RT throttling activated
----------------
Code disassembly (best guess):
   0:	25 28 00 00 00       	and    $0x28,%eax
   5:	48 3b 44 24 08       	cmp    0x8(%rsp),%rax
   a:	0f 85 52 01 00 00    	jne    0x162
  10:	89 d8                	mov    %ebx,%eax
  12:	48 83 c4 10          	add    $0x10,%rsp
  16:	5b                   	pop    %rbx
  17:	41 5c                	pop    %r12
  19:	41 5d                	pop    %r13
  1b:	41 5e                	pop    %r14
  1d:	41 5f                	pop    %r15
  1f:	5d                   	pop    %rbp
  20:	c3                   	retq
  21:	48 c7 04 24 00 00 00 	movq   $0x0,(%rsp)
  28:	00
  29:	9c                   	pushfq
* 2a:	8f 04 24             	popq   (%rsp) <-- trapping instruction
  2d:	4c 8b 24 24          	mov    (%rsp),%r12
  31:	bd 00 02 00 00       	mov    $0x200,%ebp
  36:	be 00 02 00 00       	mov    $0x200,%esi
  3b:	4c 21 e6             	and    %r12,%rsi
  3e:	31 ff                	xor    %edi,%edi

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/01/16 14:41 upstream d0a231f01e5b 723cfaf0 .config log report info INFO: rcu detected stall in vfs_write
* Struck through repros no longer work on HEAD.