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INFO: rcu detected stall in wait4 (6)

Status: auto-obsoleted due to no activity on 2025/05/29 01:55
Subsystems: kernel
[Documentation on labels]
First crash: 144d, last: 144d
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in wait4 (3) kernel 1 2 889d 894d 0/29 auto-obsoleted due to no activity on 2023/05/14 12:43
upstream INFO: rcu detected stall in wait4 kernel 1 2 1506d 1563d 0/29 auto-closed as invalid on 2021/09/04 10:15
upstream INFO: rcu detected stall in wait4 (5) fs 1 6 263d 293d 0/29 auto-obsoleted due to no activity on 2025/01/30 05:34
upstream INFO: rcu detected stall in wait4 (4) kernel 1 C error done 35 406d 735d 0/29 auto-obsoleted due to no activity on 2024/09/18 16:22
upstream INFO: rcu detected stall in wait4 (2) kernel 1 2 1091d 1173d 0/29 auto-obsoleted due to no activity on 2022/10/24 16:24

Sample crash report:
vkms_vblank_simulate: vblank timer overrun
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=34285, q=351 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294968550-4294958048), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g34285 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:28344 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6857
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </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 UID: 0 PID: 10903 Comm: syz-executor Not tainted 6.14.0-rc4-syzkaller-00169-g1e15510b71c9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__kasan_check_read+0x0/0x20 mm/kasan/shadow.c:30
Code: c3 cc cc cc cc 48 83 c4 60 48 c7 c7 68 e9 7f 8d 5b 5d 41 5c e9 11 37 7c ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 0c 24 89 f6 31 d2 e9 7f f0 ff ff 66 66 2e 0f 1f
RSP: 0018:ffffc90000a18ad8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 1ffff11006552a7c RSI: 0000000000000008 RDI: ffffffff96ec2cc0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 000000000000000a R11: 0000000000000002 R12: 0000000000000002
R13: ffff888032a94880 R14: 0000000000000000 R15: ffff888032a953c0
FS:  0000555590667500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f718ff8 CR3: 0000000024b5e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class+0x4e/0x130 kernel/locking/lockdep.c:230
 check_wait_context kernel/locking/lockdep.c:4852 [inline]
 __lock_acquire+0x410/0x3c40 kernel/locking/lockdep.c:5178
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x13b/0x370 lib/debugobjects.c:873
 debug_hrtimer_deactivate kernel/time/hrtimer.c:460 [inline]
 debug_deactivate kernel/time/hrtimer.c:502 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1769 [inline]
 __hrtimer_run_queues+0x47c/0xae0 kernel/time/hrtimer.c:1865
 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:246
Code: cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 8f ff 49 7e <65> 8b 05 90 ff 49 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00
RSP: 0018:ffffc9000dd8faf8 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffffc9000dd8fce8 RCX: ffffffff817b314d
RDX: ffff888032a94880 RSI: 0000000000000010 RDI: 0000000000000005
RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888061272440 R14: 1ffff92001bb1f9d R15: ffff8880612729b0
 wait_consider_task+0xbd/0x4100 kernel/exit.c:1433
 do_wait_thread kernel/exit.c:1539 [inline]
 __do_wait+0x1e2/0x890 kernel/exit.c:1657
 do_wait+0x217/0x570 kernel/exit.c:1691
 kernel_wait4+0x16c/0x280 kernel/exit.c:1850
 __do_sys_wait4+0x15f/0x170 kernel/exit.c:1878
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc09f7833d7
Code: 89 7c 24 10 48 89 4c 24 18 e8 45 1b 03 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 95 1b 03 00 8b 44
RSP: 002b:00007ffdefa554a0 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 00000000000000a8 RCX: 00007fc09f7833d7
RDX: 0000000040000001 RSI: 00007ffdefa5550c RDI: 00000000ffffffff
RBP: 00007ffdefa5550c R08: 0000000000000000 R09: 00007fc0a057d000
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000004f
R13: 00000000000927c0 R14: 0000000000033021 R15: 00007ffdefa55560
 </TASK>
vkms_vblank_simulate: vblank timer overrun

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/28 01:49 upstream 1e15510b71c9 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in wait4
* Struck through repros no longer work on HEAD.