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INFO: rcu detected stall in do_idle

Status: upstream: reported on 2025/06/24 01:25
Reported-by: syzbot+1d0ebb5530b0023d4b6b@syzkaller.appspotmail.com
First crash: 3d14h, last: 3d14h
▶ ▼ Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 BUG: soft lockup in do_idle origin:upstream C error 472 5h31m 759d 0/3 upstream: reported C repro on 2023/05/29 19:14
android-414 INFO: rcu detected stall in do_idle 1 2478d 2478d 0/1 auto-closed as invalid on 2019/03/13 10:31
linux-4.19 INFO: rcu detected stall in do_idle (2) 2 1158d 1158d 0/1 auto-closed as invalid on 2022/08/24 07:48
linux-4.19 INFO: rcu detected stall in do_idle 1 2016d 2016d 0/1 auto-closed as invalid on 2020/04/18 00:25
linux-4.14 INFO: rcu detected stall in do_idle 4 2111d 2117d 0/1 auto-closed as invalid on 2020/01/14 08:59
upstream INFO: rcu detected stall in do_idle x86 acpi C done error 3140 5h57m 2449d 0/29 upstream: reported C repro on 2018/10/13 07:31
linux-4.14 INFO: rcu detected stall in do_idle (2) C error 4 1032d 1162d 0/1 upstream: reported C repro on 2022/04/22 10:09
linux-6.1 BUG: soft lockup in do_idle origin:upstream C 43 4d06h 748d 0/3 upstream: reported C repro on 2023/06/10 08:51

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7172/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=15641, q=80 ncpus=2)
task:syz.0.283       state:R  running task     stack:25608 pid:7172  ppid:5764   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867
 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6891
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 zap_pte_range mm/memory.c:1522 [inline]
 zap_pmd_range mm/memory.c:1570 [inline]
 zap_pud_range mm/memory.c:1599 [inline]
 zap_p4d_range mm/memory.c:1620 [inline]
 unmap_page_range+0x236f/0x2fe0 mm/memory.c:1641
 unmap_vmas+0x25e/0x3a0 mm/memory.c:1731
 exit_mmap+0x200/0xb50 mm/mmap.c:3292
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x886/0x23c0 kernel/exit.c:861
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1023
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3a4998e929
RSP: 002b:00007f3a4a7b30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f3a49bb6088 RCX: 00007f3a4998e929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3a49bb6088
RBP: 00007f3a49bb6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3a49bb608c
R13: 0000000000000000 R14: 00007fff7efcb1a0 R15: 00007fff7efcb288
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g15641 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=15126
rcu: rcu_preempt kthread starved for 10503 jiffies! g15641 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27496 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.6.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0xb3/0x8b0 kernel/locking/lockdep.c:5765
Code: 9c 7e 83 f8 08 0f 83 24 05 00 00 89 c3 c1 e8 06 48 8d 3c c5 28 ab 49 8e be 08 00 00 00 e8 85 c3 76 00 48 0f a3 1d f5 2f e2 0c <73> 0d e8 26 15 08 00 84 c0 0f 84 2c 05 00 00 48 c7 c0 dc df 49 8e
RSP: 0018:ffffc90000007b40 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81677b2b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e49ab28
RBP: ffffc90000007c60 R08: ffffffff8e49ab2f R09: 1ffffffff1c93565
R10: dffffc0000000000 R11: fffffbfff1c93566 R12: ffffffff88954949
R13: dffffc0000000000 R14: 18535bd6fc000000 R15: 1ffff92000000f74
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f58f074d550 CR3: 0000000063eac000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:344 [inline]
 rcu_read_unlock include/linux/rcupdate.h:819 [inline]
 advance_sched+0xb29/0xc80 net/sched/sch_taprio.c:998
 __run_hrtimer kernel/time/hrtimer.c:1755 [inline]
 __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 63 f0 41 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2
RAX: 18da0511c23bf800 RBX: ffffffff81618a7b RCX: 18da0511c23bf800
RDX: 0000000000000001 RSI: ffffffff8aaab2c0 RDI: ffffffff8afc6900
RBP: ffffffff8ca07eb8 R08: ffff8880b8e36d4b R09: 1ffff110171c6da9
R10: dffffc0000000000 R11: ffffed10171c6daa R12: ffffffff8e49ab28
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952670
 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:753
 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
 cpuidle_idle_call kernel/sched/idle.c:170 [inline]
 do_idle+0x1eb/0x510 kernel/sched/idle.c:282
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
 rest_init+0x2e2/0x300 init/main.c:732
 arch_call_rest_init+0xe/0x10 init/main.c:829
 start_kernel+0x459/0x4e0 init/main.c:1074
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
 secondary_startup_64_no_verify+0x179/0x17b
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 01:24 linux-6.6.y 6282921b6825 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan INFO: rcu detected stall in do_idle
* Struck through repros no longer work on HEAD.