INFO: rcu detected stall in schedule_tail

Status: auto-obsoleted due to no activity on 2024/10/21 04:18
Reported-by: syzbot+518239308dc84a8ff326@syzkaller.appspotmail.com
First crash: 761d, last: 761d
▶ ▼ Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in schedule_tail (4) arm 1 2 1163d 1240d 0/29 auto-obsoleted due to no activity on 2023/09/05 02:08
linux-6.1 INFO: rcu detected stall in schedule_tail (2) 1 1 92d 92d 0/3 upstream: reported on 2026/05/13 04:49
upstream INFO: rcu detected stall in schedule_tail (7) mm 1 1 416d 416d 0/29 auto-obsoleted due to no activity on 2025/08/22 04:05
upstream INFO: rcu detected stall in schedule_tail mm 1 145 2444d 2445d 0/29 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in schedule_tail (3) cgroups mm 1 40 2409d 2409d 0/29 closed as invalid on 2020/01/09 08:13
linux-6.6 INFO: rcu detected stall in schedule_tail origin:lts-only 1 syz, C error 1 130d 130d 0/2 upstream: reported C repro on 2026/04/04 18:44
upstream INFO: rcu detected stall in schedule_tail (5) mm 1 2 1035d 1036d 0/29 auto-obsoleted due to no activity on 2024/01/11 06:31
upstream INFO: rcu detected stall in schedule_tail (8) prio:low mm 1 syz, C error error 1 200d 198d 0/29 upstream: reported C repro on 2026/01/27 01:07
upstream INFO: rcu detected stall in schedule_tail (6) mm 1 syz, C 8 584d 678d 0/29 auto-obsoleted due to no activity on 2025/04/16 03:50
upstream INFO: rcu detected stall in schedule_tail (2) mm 1 26 2409d 2409d 0/29 closed as invalid on 2020/01/08 05:23

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3627/1:b..l P3002/1:b..l P3759/1:b..l
	(detected by 1, t=10502 jiffies, g=7237, q=26 ncpus=2)
task:syz-executor    state:R  running task     stack:28440 pid:3759  ppid:3553   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666
Code: 2b 00 74 08 4c 89 f7 e8 ef ae 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90004bc7920 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000978f30 RCX: 1ffff92000978ed0
RDX: dffffc0000000000 RSI: ffffffff8aec13c0 RDI: ffffffff8b3d47e0
RBP: ffffc90004bc7a68 R08: dffffc0000000000 R09: fffffbfff2093845
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000978f2c
R13: dffffc0000000000 R14: ffffc90004bc7980 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 count_memcg_event_mm+0xad/0x410 include/linux/memcontrol.h:1095
 handle_mm_fault+0x15b/0x5340 mm/memory.c:5254
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0010:__put_user_nocheck_4+0x3/0x11
Code: 00 00 48 39 d9 73 54 0f 01 cb 66 89 01 31 c9 0f 01 ca c3 0f 1f 44 00 00 48 bb fd ef ff ff ff 7f 00 00 48 39 d9 73 34 0f 01 cb <89> 01 31 c9 0f 01 ca c3 66 0f 1f 44 00 00 48 bb f9 ef ff ff ff 7f
RSP: 0018:ffffc90004bc7f28 EFLAGS: 00050293
RAX: 0000000000000017 RBX: 00007fffffffeffd RCX: 00005555570f97d0
RDX: 0000000000000000 RSI: ffffffff8aec13c0 RDI: ffffffff8b3d47e0
RBP: ffff888020ae2450 R08: dffffc0000000000 R09: fffffbfff1ce702e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000017 R15: dffffc0000000000
 schedule_tail+0x91/0xb0 kernel/sched/core.c:5184
 ret_from_fork+0x8/0x30 arch/x86/entry/entry_64.S:293
 </TASK>
task:udevd           state:R  running task     stack:24688 pid:3002  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:do___read_seqcount_retry include/linux/seqlock.h:429 [inline]
RIP: 0010:do_read_seqcount_retry include/linux/seqlock.h:449 [inline]
RIP: 0010:read_seqretry include/linux/seqlock.h:862 [inline]
RIP: 0010:__follow_mount_rcu fs/namei.c:1513 [inline]
RIP: 0010:handle_mounts fs/namei.c:1534 [inline]
RIP: 0010:step_into+0x89e/0x1070 fs/namei.c:1836
Code: 00 00 45 8b 24 24 48 89 d8 48 c1 e8 03 42 0f b6 04 30 84 c0 0f 85 62 01 00 00 44 8b 3b 48 8b 84 24 88 00 00 00 42 0f b6 04 30 <84> c0 0f 85 67 01 00 00 8b 05 b4 25 ec 0a 44 39 f8 0f 85 56 05 00
RSP: 0018:ffffc900031ef680 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc900031efbe8 RCX: ffff88807bdd8000
RDX: ffffc900031efbe4 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900031ef7d0 R08: ffffffff81f520d4 R09: fffffbfff1ce702e
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000200000
R13: ffffc900031efba0 R14: dffffc0000000000 R15: 0000000000000764
 walk_component fs/namei.c:2004 [inline]
 link_path_walk+0x72c/0xee0 fs/namei.c:2325
 path_openat+0x23d/0x2e60 fs/namei.c:3781
 do_filp_open+0x230/0x480 fs/namei.c:3812
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5e5b1169a4
RSP: 002b:00007fff3a4a1bd0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000008 RCX: 00007f5e5b1169a4
RDX: 0000000000080000 RSI: 00007fff3a4a1d08 RDI: 00000000ffffff9c
RBP: 00007fff3a4a1d08 R08: 0000000000000008 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000
R13: 0000557dd8bb9b42 R14: 0000000000000001 R15: 0000000000000000
 </TASK>
task:kworker/u4:5    state:R  running task     stack:24320 pid:3627  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666
Code: 2b 00 74 08 4c 89 f7 e8 ef ae 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc900042bfa80 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000857f5c RCX: 1ffff92000857efc
RDX: dffffc0000000000 RSI: ffffffff8aec13c0 RDI: ffffffff8b3d47e0
RBP: ffffc900042bfbe0 R08: dffffc0000000000 R09: fffffbfff2093845
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000857f58
R13: dffffc0000000000 R14: ffffc900042bfae0 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xe8/0x610 net/batman-adv/network-coding.c:719
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: rcu_preempt kthread starved for 10583 jiffies! g7237 f0x0 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:27256 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572
Code: 27 f5 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 e4 e5 fb f6 0f 1f 44 00 00 e8 3a 23 f5 f6 0f 00 2d 83 f4 b1 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 5b a7 4c f7
RSP: 0018:ffffc90000177b80 EFLAGS: 000002d3
RAX: ffffffff8a957316 RBX: 0000000000000000 RCX: ffff888012731dc0
RDX: 0000000000000000 RSI: ffffffff8aec0240 RDI: ffffffff8b3d47e0
RBP: ffffc90000177c10 R08: ffffffff8a9572f8 R09: ffffed10024e63b9
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200002ef70
R13: ffff888017f08004 R14: ffffc90000177ba0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005d95d000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:709
 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
 call_cpuidle kernel/sched/idle.c:155 [inline]
 cpuidle_idle_call kernel/sched/idle.c:236 [inline]
 do_idle+0x3ce/0x680 kernel/sched/idle.c:303
 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
 start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xcf/0xdb
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/13 04:17 linux-6.1.y 266ee8e06d5b eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in schedule_tail
* Struck through repros no longer work on HEAD.