syzbot


INFO: rcu detected stall in sys_move_pages

Status: auto-closed as invalid on 2022/02/07 20:19
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 397d, last: 381d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=268261, q=15)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295128941-4295118439), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g268261 f0x2 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:28696 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4969 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6250
 schedule+0xd2/0x260 kernel/sched/core.c:6323
 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 1
CPU: 1 PID: 4328 Comm: syz-executor.2 Not tainted 5.15.0-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+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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+0x2125/0x2200 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:1421
 __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:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197
Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 c9 a9 8a 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b
RSP: 0018:ffffc900171ffc00 EFLAGS: 00000287
RAX: 000000001ffff000 RBX: ffffc900171ffd58 RCX: 000000001ffff000
RDX: 0000000000000000 RSI: ffff8880315f5700 RDI: 0000000000000003
RBP: 00000000fffffff2 R08: 0000000000000000 R09: ffff8880794046bf
R10: ffffffff81bee383 R11: 0000000000000000 R12: ffffc900171ffcc8
R13: 0000000000000000 R14: 000000000000000c R15: dffffc0000000000
 do_pages_stat_array mm/migrate.c:1893 [inline]
 do_pages_stat+0x2e9/0x5e0 mm/migrate.c:1948
 kernel_move_pages+0xcd4/0x14e0 mm/migrate.c:2035
 __do_sys_move_pages mm/migrate.c:2046 [inline]
 __se_sys_move_pages mm/migrate.c:2041 [inline]
 __x64_sys_move_pages+0xdd/0x1b0 mm/migrate.c:2041
 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: 0033:0x7f0a6a565ae9
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:00007f0a67adb188 EFLAGS: 00000246 ORIG_RAX: 0000000000000117
RAX: ffffffffffffffda RBX: 00007f0a6a678f60 RCX: 00007f0a6a565ae9
RDX: 0000000020000080 RSI: 0000000020000047 RDI: 0000000000000000
RBP: 00007f0a6a5bff45 R08: 0000000020000100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0a6abacb2f R14: 00007f0a67adb300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	01 f0                	add    %esi,%eax
   2:	4d 89 03             	mov    %r8,(%r11)
   5:	e9 63 fd ff ff       	jmpq   0xfffffd6d
   a:	b9 ff ff ff ff       	mov    $0xffffffff,%ecx
   f:	ba 08 00 00 00       	mov    $0x8,%edx
  14:	4d 8b 03             	mov    (%r11),%r8
  17:	48 0f bd ca          	bsr    %rdx,%rcx
  1b:	49 8b 45 00          	mov    0x0(%r13),%rax
  1f:	48 63 c9             	movslq %ecx,%rcx
  22:	e9 64 ff ff ff       	jmpq   0xffffff8b
  27:	0f 1f 00             	nopl   (%rax)
* 2a:	65 8b 05 c9 a9 8a 7e 	mov    %gs:0x7e8aa9c9(%rip),%eax        # 0x7e8aa9fa <-- trapping instruction
  31:	89 c1                	mov    %eax,%ecx
  33:	48 8b 34 24          	mov    (%rsp),%rsi
  37:	81 e1 00 01 00 00    	and    $0x100,%ecx
  3d:	65                   	gs
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2021/11/09 20:15 upstream d2f38a3c6507 59bcaf9a .config log report info INFO: rcu detected stall in sys_move_pages
ci-upstream-kasan-gce 2021/11/09 19:42 upstream d2f38a3c6507 59bcaf9a .config log report info INFO: rcu detected stall in sys_move_pages
ci-upstream-kasan-gce 2021/11/03 01:33 upstream bfc484fe6abb 17f3edd2 .config log report info INFO: rcu detected stall in sys_move_pages
ci-upstream-linux-next-kasan-gce-root 2021/10/25 04:35 linux-next cf6c9d12750c 4f0000ee .config log report info INFO: rcu detected stall in sys_move_pages
* Struck through repros no longer work on HEAD.