syzbot


INFO: rcu detected stall in schedule_timeout

Status: upstream: reported C repro on 2024/05/22 14:45
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+7cb65445f1326f641b08@syzkaller.appspotmail.com
First crash: 25d, last: 5d18h
Bug presence (1)
Date Name Commit Repro Result
2024/05/23 upstream (ToT) c760b3725e52 C [report] INFO: rcu detected stall in schedule_timeout
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in schedule_timeout (3) cgroups mm 11 1621d 1621d 0/27 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in schedule_timeout (2) kernel 2 1621d 1621d 0/27 closed as invalid on 2020/01/08 05:23
upstream INFO: rcu detected stall in schedule_timeout (4) kernel 1 326d 326d 0/27 closed as invalid on 2023/09/01 06:44
linux-6.1 INFO: rcu detected stall in schedule_timeout 21 3d03h 59d 0/3 upstream: reported on 2024/04/18 03:48
upstream INFO: rcu detected stall in schedule_timeout (5) kernel 2 232d 267d 0/27 auto-obsoleted due to no activity on 2024/01/26 16:31
upstream INFO: rcu detected stall in schedule_timeout cgroups mm 69 1656d 1657d 0/27 closed as invalid on 2019/12/04 14:14
upstream INFO: rcu detected stall in schedule_timeout (6) usb C done 16 2d10h 30d 0/27 upstream: reported C repro on 2024/05/16 19:17

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=3685, q=6)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294967356-4294956854), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g3685 f0x2 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:25688 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:preempt_count_add+0x32/0x180 kernel/sched/core.c:5485
Code: c7 c0 c0 ff 3e 91 48 c1 e8 03 49 bf 00 00 00 00 00 fc ff df 42 0f b6 04 38 84 c0 0f 85 e2 00 00 00 83 3d 20 9f e7 0f 00 75 07 <65> 8b 05 1f 0f ab 7e 65 01 1d 18 0f ab 7e 48 c7 c0 c0 ff 3e 91 48
RSP: 0018:ffffc90000d47b50 EFLAGS: 00000246
RAX: 0000000000000004 RBX: 0000000000000001 RCX: ffffffff913eff03
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
RBP: ffffc90000d47c90 R08: dffffc0000000000 R09: ffffed1027fc4771
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88813fe23b80 R14: 0000000000000000 R15: dffffc0000000000
 schedule+0x114/0x1f0 kernel/sched/core.c:6458
 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:300
 </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: 3522 Comm: syz-executor220 Not tainted 5.15.159-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:__rcu_read_unlock+0x65/0x100 kernel/rcu/tree_plugin.h:421
Code: b6 04 23 84 c0 75 69 41 89 6d 00 85 ed 75 1d 4d 8d be 40 04 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 75 78 41 83 3f 00 <75> 23 42 0f b6 04 23 84 c0 75 52 41 8b 45 00 3d 00 00 00 40 73 0b
RSP: 0018:ffffc90000007da8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 1ffff1100f01b087 RCX: ffff8880780d8000
RDX: 0000000080010001 RSI: ffffffff8ad8f660 RDI: ffffffff8ad8f620
RBP: 0000000000000000 R08: ffffffff814f8faf R09: fffffbfff1f7f019
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880780d843c R14: ffff8880780d8000 R15: ffff8880780d8440
FS:  00007ffa697516c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffa69750e40 CR3: 0000000023c1b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 group_send_sig_info+0x18e/0x2d0 kernel/signal.c:1439
 do_bpf_send_signal+0x81/0x150 kernel/trace/bpf_trace.c:779
 irq_work_single kernel/irq_work.c:155 [inline]
 irq_work_run_list+0x20b/0x370 kernel/irq_work.c:177
 irq_work_run+0x63/0xe0 kernel/irq_work.c:186
 __sysvec_irq_work+0x9a/0x250 arch/x86/kernel/irq_work.c:22
 sysvec_irq_work+0x89/0xb0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:664
RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4785
Code: 45 31 c9 68 b7 90 59 81 e8 cc 1a 09 00 48 83 c4 08 4c 89 ff e8 60 da fe ff 66 90 4c 89 ff e8 f6 ea cd 08 e8 d1 4b 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:ffffc90002ce7698 EFLAGS: 00000286
RAX: c912400c68919f00 RBX: ffff8880780dbbb4 RCX: ffffffff913eff03
RDX: dffffc0000000000 RSI: ffffffff8a8b2980 RDI: ffffffff8ad8f680
RBP: ffffc90002ce7710 R08: ffffffff8186dcf0 R09: ffffed1017347469
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff11017347613 R14: ffff8880b9a3b098 R15: ffff8880b9a3a340
 finish_task_switch+0x134/0x630 kernel/sched/core.c:4902
 context_switch kernel/sched/core.c:5033 [inline]
 __schedule+0x12cc/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x25b/0x480 kernel/futex/core.c:2863
 futex_wait+0x2f8/0x740 kernel/futex/core.c:2964
 do_futex+0x1414/0x1810 kernel/futex/core.c:3982
 __do_sys_futex kernel/futex/core.c:4059 [inline]
 __se_sys_futex+0x407/0x490 kernel/futex/core.c:4040
 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: 0033:0x7ffa697905d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffa69751228 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007ffa6981a308 RCX: 00007ffa697905d9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffa6981a308
RBP: 00007ffa6981a300 R08: 00007ffa697516c0 R09: 00007ffa697516c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffa697e7074
R13: b635773f06ebbeef R14: 656c6c616b7a7973 R15: 00007ffe8444ce18
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.509 msecs

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/23 05:50 linux-5.15.y 83655231580b 4d098039 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in schedule_timeout
2024/06/10 21:57 linux-5.15.y c61bd26ae81a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in schedule_timeout
2024/06/10 21:53 linux-5.15.y c61bd26ae81a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in schedule_timeout
2024/05/23 03:37 linux-5.15.y 83655231580b 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in schedule_timeout
2024/05/22 14:44 linux-5.15.y 83655231580b 4d098039 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in schedule_timeout
* Struck through repros no longer work on HEAD.