syzbot


INFO: rcu detected stall in gc_worker

Status: upstream: reported C repro on 2023/07/03 02:12
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+458308355e7401f2f4c5@syzkaller.appspotmail.com
First crash: 245d, last: 9d17h
Bug presence (1)
Date Name Commit Repro Result
2023/07/05 upstream (ToT) d528014517f2 C [report] INFO: rcu detected stall in corrupted
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in gc_worker (2) netfilter C unreliable 4 778d 816d 0/26 closed as invalid on 2022/02/08 10:33
upstream INFO: rcu detected stall in gc_worker (3) netfilter C done 47 35d 715d 0/26 upstream: reported C repro on 2022/03/20 12:02
upstream INFO: rcu detected stall in gc_worker netfilter 8 1783d 1868d 0/26 auto-closed as invalid on 2019/10/14 16:34
linux-5.15 INFO: rcu detected stall in gc_worker origin:upstream C 6 22d 211d 0/3 upstream: reported C repro on 2023/08/06 21:00
linux-4.19 INFO: rcu detected stall in gc_worker syz error 1 682d 682d 0/1 upstream: reported syz repro on 2022/04/22 15:43
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2024/02/16 22:50 2h26m bisect fix linux-6.1.y job log (0) log
2024/01/07 17:15 2h06m bisect fix linux-6.1.y job log (0) log
2023/11/26 07:58 2h12m bisect fix linux-6.1.y job log (0) log
2023/10/24 21:30 2h00m bisect fix linux-6.1.y job log (0) log
2023/09/18 17:35 2h25m bisect fix linux-6.1.y job log (0) log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P151/1:b..l
	(detected by 0, t=10502 jiffies, g=48301, q=2 ncpus=2)
task:kworker/0:2     state:R  running task     stack:25496 pid:151   ppid:2      flags:0x00004000
Workqueue: events_power_efficient gc_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:433
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:seqcount_lockdep_reader_access+0x1dc/0x220 include/linux/seqlock.h:105
Code: f8 4d 85 ed 75 16 e8 33 60 c6 f8 eb 15 e8 2c 60 c6 f8 e8 97 79 c6 01 4d 85 ed 74 ea e8 1d 60 c6 f8 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc90002dffa40 EFLAGS: 00000293
RAX: ffffffff88c41ed3 RBX: 0000000000000000 RCX: ffff888018711dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002dffaf0 R08: ffffffff88c41ea9 R09: fffffbfff2092656
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000046 R15: 1ffff920005bff48
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:335 [inline]
 gc_worker+0x325/0x1530 net/netfilter/nf_conntrack_core.c:1503
 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:306
 </TASK>
rcu: rcu_preempt kthread starved for 10526 jiffies! g48301 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:25528 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:1935
 rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 10702 Comm: syz-executor297 Not tainted 6.1.79-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 31 bc f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 be 96 d5 f6 48 89 df e8 26 d4 d6 f6 e8 01 63 fc f6 fb bf 01 00 00 00 <e8> b6 62 c9 f6 65 8b 05 f7 92 6d 75 85 c0 74 02 5b c3 e8 34 b1 6b
RSP: 0018:ffffc9000b417b30 EFLAGS: 00000286
RAX: 3f2417c04eade800 RBX: ffff8880281a3780 RCX: ffffffff91c8b103
RDX: dffffc0000000000 RSI: ffffffff8aebed40 RDI: 0000000000000001
RBP: ffffc9000b417c70 R08: dffffc0000000000 R09: ffffed10050346f1
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11005034783
R13: 000000001c000004 R14: 0000000000000021 R15: ffff8880281a3c18
FS:  00007f209cc346c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f209ccc9e78 CR3: 000000006fc09000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 spin_unlock_irq include/linux/spinlock.h:401 [inline]
 get_signal+0x154b/0x17d0 kernel/signal.c:2865
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:168
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f209cc737a7
Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 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
RSP: 002b:00007f209cc34238 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f209ccfd308 RCX: 00007f209cc737a9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f209ccfd308
RBP: 00007f209ccfd300 R08: 00007f209cc346c0 R09: 00007f209cc346c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f209ccfd30c
R13: 0000000000000011 R14: 00007fff572bd370 R15: 00007fff572bd458
 </TASK>

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/24 05:36 linux-6.1.y 81e1dc2f7001 8d446f15 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in gc_worker
2023/07/03 08:44 linux-6.1.y 0f4ac6b4c5f0 bfc47836 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in gc_worker
2023/07/03 02:12 linux-6.1.y 0f4ac6b4c5f0 bfc47836 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in gc_worker
2024/02/21 16:35 linux-6.1.y 8b4118fabd6e 3af7dd65 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in gc_worker
2023/12/08 15:51 linux-6.1.y 6c6a6c7e211c 28b24332 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in gc_worker
2023/12/07 11:55 linux-6.1.y c6114c845984 0a02ce36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in gc_worker
* Struck through repros no longer work on HEAD.