syzbot

 sign-in | mailing list | source | docs
🐞 Open [853]
🐞 Fixed [87]
🐞 Invalid [1356]
⬇ Missing Backports [132]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in msr_read

Status: auto-obsoleted due to no activity on 2024/11/29 20:07
Reported-by: syzbot+8c65e253a599b0915122@syzkaller.appspotmail.com
First crash: 664d, last: 664d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in msr_read kernel 1 8 676d 737d 0/29 auto-obsoleted due to no activity on 2024/11/07 00:24
linux-6.1 INFO: rcu detected stall in msr_read 1 2 674d 733d 0/3 auto-obsoleted due to no activity on 2024/11/19 16:03
upstream INFO: rcu detected stall in msr_read (2) lsm 1 36 285d 334d 0/29 auto-obsoleted due to no activity on 2025/12/13 17:39
linux-5.15 INFO: rcu detected stall in msr_read (2) 1 1 30d 30d 0/3 upstream: reported on 2026/05/17 04:25

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 ticks this GP) idle=729/1/0x4000000000000000 softirq=7345/7345 fqs=0 
	(detected by 0, t=10502 jiffies, g=7137, q=35)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4137 Comm: syz.0.141 Not tainted 5.15.165-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:arch_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline]
RIP: 0010:atomic64_read include/linux/atomic/atomic-instrumented.h:606 [inline]
RIP: 0010:taprio_set_budget net/sched/sch_taprio.c:556 [inline]
RIP: 0010:advance_sched+0x60c/0x940 net/sched/sch_taprio.c:761
Code: 00 00 48 83 c3 20 48 8b 44 24 28 8b 00 4c 69 f0 e8 03 00 00 4c 8b 6c 24 48 49 8d 6d a0 48 89 ef be 08 00 00 00 e8 44 f2 48 f9 <48> 89 e8 48 c1 e8 03 42 80 3c 20 00 4c 8b 64 24 50 74 08 48 89 ef
RSP: 0018:ffffc90000dd0cc0 EFLAGS: 00000056
RAX: 0000000004000001 RBX: ffff88801d8ff9a0 RCX: ffffffff888139bc
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88801ee29ae0
RBP: ffff88801ee29ae0 R08: dffffc0000000000 R09: ffffed1003dc535d
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88801ee29b40 R14: 0000000fa0000000 R15: 17f9e7a9e4000000
FS:  00007f2b326936c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020025000 CR3: 0000000058618000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4782
Code: 45 31 c9 68 37 9b 59 81 e8 9c 11 09 00 48 83 c4 08 4c 89 ff e8 50 db fe ff eb 32 4c 89 ff e8 e6 47 e3 08 e8 c1 46 2d 00 fb 5b <41> 5c 41 5d 41 5e 41 5f c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 87
RSP: 0018:ffffc900033d7558 EFLAGS: 00000282
RAX: 0cfc3a5f25b38000 RBX: ffff88801f4f1df4 RCX: ffffffff91468f03
RDX: dffffc0000000000 RSI: ffffffff8a8b2a20 RDI: ffffffff8ad8f7c0
RBP: ffffc900033d75d0 R08: ffffffff8186e260 R09: ffffed1017347461
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff1101736760b R14: ffff8880b9b3b058 R15: ffff8880b9a3a300
 finish_task_switch+0x134/0x630 kernel/sched/core.c:4899
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12cc/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0xac/0x300 kernel/time/timer.c:1890
 do_wait_for_common+0x2d9/0x480 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
 rdmsr_safe_on_cpu+0x168/0x310 arch/x86/lib/msr-smp.c:183
 msr_read+0x168/0x1f0 arch/x86/kernel/msr.c:67
 vfs_read+0x2fc/0xe10 fs/read_write.c:483
 ksys_read+0x1a2/0x2c0 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2b34216e79
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b32693038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f2b343b2f80 RCX: 00007f2b34216e79
RDX: 0000000000018ff8 RSI: 0000000020019680 RDI: 0000000000000003
RBP: 00007f2b34284916 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2b343b2f80 R15: 00007fff56479798
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g7137 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26712 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.15.165-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562
Code: 8a 43 f7 48 83 e3 08 0f 85 0a 01 00 00 4c 8d 74 24 20 e8 24 07 4a f7 0f 1f 44 00 00 e8 8a 86 43 f7 0f 00 2d c3 50 a6 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 bb 4f 8d f7
RSP: 0018:ffffffff8c607b80 EFLAGS: 000002d3
RAX: ffffffff8a3cdb16 RBX: 0000000000000000 RCX: ffffffff8c6bd5c0
RDX: 0000000000000000 RSI: ffffffff8a8b2a20 RDI: ffffffff8ad8f7c0
RBP: ffffffff8c607c10 R08: ffffffff8186e260 R09: fffffbfff18d7ab9
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff18c0f70
R13: ffff888018a35804 R14: ffffffff8c607ba0 R15: dffffc0000000000
 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:697
 cpuidle_enter_state+0x521/0xef0 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x3e4/0x670 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_kernel+0x48c/0x540 init/main.c:1140
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/21 20:06 linux-5.15.y fa93fa65db6e db5852f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in msr_read
* Struck through repros no longer work on HEAD.