syzbot


INFO: rcu detected stall in schedule_tail (6)

Status: upstream: reported C repro on 2024/10/03 16:14
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+4d2bdddae2e3866013ef@syzkaller.appspotmail.com
First crash: 265d, last: 81d
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly virt report (Jan 2025) 0 (1) 2025/01/14 08:53
[syzbot] [net?] [virt?] INFO: rcu detected stall in schedule_tail (6) 0 (1) 2024/10/03 16:14
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in schedule_tail (4) arm 2 660d 737d 0/28 auto-obsoleted due to no activity on 2023/09/05 02:08
linux-6.1 INFO: rcu detected stall in schedule_tail 1 258d 258d 0/3 auto-obsoleted due to no activity on 2024/10/21 04:18
upstream INFO: rcu detected stall in schedule_tail kernel 145 1940d 1942d 0/28 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in schedule_tail (3) cgroups mm 40 1905d 1906d 0/28 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in schedule_tail (5) mm 2 532d 533d 0/28 auto-obsoleted due to no activity on 2024/01/11 06:31
upstream INFO: rcu detected stall in schedule_tail (2) kernel 26 1906d 1906d 0/28 closed as invalid on 2020/01/08 05:23
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/11/01 22:26 16m retest repro https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing OK log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=512c/1/0x4000000000000000 softirq=88313/88314 fqs=8
rcu: 	(detected by 0, t=10505 jiffies, g=71369, q=492 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 21023 Comm: syz.6.3976 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kasan_check_range+0x5/0x290 mm/kasan/generic.c:188
Code: 50 b8 07 8e e8 2c 6f e3 ff 90 0f 0b 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 <41> 57 41 56 41 54 53 b0 01 48 85 f6 0f 84 a0 01 00 00 4c 8d 04 37
RSP: 0018:ffffc90000a18a30 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff817ae6e0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90198130
RBP: ffffc90000a18b70 R08: 0000000000000003 R09: fffff52000143160
R10: dffffc0000000000 R11: fffff52000143160 R12: 1ffff92000143154
R13: ffffffff84c8b605 R14: ffffc90000a18ba0 R15: dffffc0000000000
FS:  00007fa0d75b06c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c306c7b CR3: 0000000047960000 CR4: 0000000000350ef0
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]
 cpumask_test_cpu include/linux/cpumask.h:570 [inline]
 cpu_online include/linux/cpumask.h:1117 [inline]
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xb0/0xa30 kernel/locking/lockdep.c:5860
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x79/0x140 kernel/locking/spinlock.c:194
 debug_object_deactivate+0x2d5/0x390 lib/debugobjects.c:888
 debug_hrtimer_deactivate kernel/time/hrtimer.c:433 [inline]
 debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:475
 __run_hrtimer kernel/time/hrtimer.c:1707 [inline]
 __hrtimer_run_queues+0x305/0xd30 kernel/time/hrtimer.c:1803
 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x112/0x420 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 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:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5243
Code: c9 50 e8 49 0c 0c 00 48 83 c4 08 4c 89 f7 e8 ed 39 00 00 e9 de 04 00 00 4c 89 f7 e8 a0 d9 5c 0a e8 0b 8c 38 00 fb 48 8b 5d c0 <48> 8d bb f8 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc900041b7eb0 EFLAGS: 00000282
RAX: a47d56b6c30fbc00 RBX: ffff888027701e00 RCX: ffffffff9a3ab903
RDX: dffffc0000000000 RSI: ffffffff8c0a98e0 RDI: ffffffff8c5fb0e0
RBP: ffffc900041b7ef8 R08: ffffffff90198137 R09: 1ffffffff2033026
R10: dffffc0000000000 R11: fffffbfff2033027 R12: 1ffff110170e7edc
R13: dffffc0000000000 R14: ffff8880b863e8c0 R15: ffff8880b873f6e0
 schedule_tail+0xf/0xb0 kernel/sched/core.c:5300
 ret_from_fork+0x24/0x80 arch/x86/kernel/process.c:143
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: rcu_preempt kthread starved for 10465 jiffies! g71369 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:25976 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0x1850/0x4c30 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6848
 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 21033 Comm: syz.5.3980 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x19f8/0x2c60 kernel/smp.c:884
Code: 89 e6 83 e6 01 31 ff e8 56 e9 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 01 e5 0b 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 e5 e4 0b 00 eb e4 44
RSP: 0018:ffffc90003c2f3e0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff110170e88e9 RCX: 0000000000080000
RDX: ffffc9000d1a9000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90003c2f5e0 R08: ffffffff81939f0a R09: 1ffffffff2854910
R10: dffffc0000000000 R11: fffffbfff2854911 R12: dffffc0000000000
R13: ffff8880b8744748 R14: ffff8880b863fac0 R15: 0000000000000001
FS:  00007fbc76ff66c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33c16ff8 CR3: 0000000061234000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1051
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2114 [inline]
 text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2324
 text_poke_bp+0xb0/0x100 arch/x86/kernel/alternative.c:2551
 __static_call_transform+0x51a/0x810 arch/x86/kernel/static_call.c:111
 arch_static_call_transform+0x141/0x380 arch/x86/kernel/static_call.c:163
 __static_call_update+0xd8/0x5e0 kernel/static_call_inline.c:147
 tracepoint_update_call kernel/tracepoint.c:271 [inline]
 tracepoint_add_func+0x844/0xaa0 kernel/tracepoint.c:319
 tracepoint_probe_register_prio_may_exist+0x122/0x190 kernel/tracepoint.c:435
 bpf_raw_tp_link_attach+0x4a3/0x700 kernel/bpf/syscall.c:3981
 bpf_raw_tracepoint_open+0x177/0x1f0 kernel/bpf/syscall.c:4012
 __sys_bpf+0x3c0/0x810 kernel/bpf/syscall.c:5832
 __do_sys_bpf kernel/bpf/syscall.c:5897 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5895 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5895
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc79185d29
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:00007fbc76ff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fbc79375fa0 RCX: 00007fbc79185d29
RDX: 0000000000000010 RSI: 00000000200000c0 RDI: 0000000000000011
RBP: 00007fbc79201b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbc79375fa0 R15: 00007ffc3c838938
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/06 03:50 upstream ab75170520d4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in schedule_tail
2024/12/10 22:35 upstream 7cb1b4663150 cfc402b4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in schedule_tail
2024/07/05 07:53 upstream 661e504db04c dc6bbff0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in schedule_tail
2024/10/15 22:02 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 64f3b5a6bc49 bde2d81c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in schedule_tail
2024/10/15 11:03 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 64f3b5a6bc49 7eb57b4a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in schedule_tail
2024/10/02 20:40 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 9852d85ec9d4 02f9582a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in schedule_tail
2024/07/22 00:04 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 3c3ff7be9729 b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in schedule_tail
2024/07/20 11:03 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 3c3ff7be9729 b88348e9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in schedule_tail
* Struck through repros no longer work on HEAD.