syzbot

 sign-in | mailing list | source | docs
🐞 Open [677]
🐞 Fixed [94]
🐞 Invalid [514]
⬇ Missing Backports [36]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in pwq_unbound_release_workfn

Status: auto-obsoleted due to no activity on 2024/11/17 13:02
Reported-by: syzbot+aa860b7a12ff04876571@syzkaller.appspotmail.com
First crash: 104d, last: 104d
▶ ▼ Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in pwq_unbound_release_workfn kernel 1 1088d 1088d 0/28 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in pwq_unbound_release_workfn (2) kernel 1 866d 866d 0/28 auto-closed as invalid on 2022/09/06 17:05
linux-5.15 INFO: rcu detected stall in pwq_unbound_release_workfn 1 13d 13d 0/3 upstream: reported on 2024/11/07 16:46
upstream INFO: rcu detected stall in pwq_unbound_release_workfn (3) kernel 1 665d 665d 0/28 auto-obsoleted due to no activity on 2023/04/25 19:12
upstream INFO: rcu detected stall in pwq_unbound_release_workfn (4) kernel 2 499d 548d 0/28 auto-obsoleted due to no activity on 2023/10/08 15:59

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 ticks this GP) idle=5644/1/0x4000000000000000 softirq=30997/30997 fqs=1
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P51/1:b..l
	(detected by 0, t=10502 jiffies, g=41781, q=138 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3690 Comm: kworker/1:3 Not tainted 6.1.103-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: events pwq_unbound_release_workfn
RIP: 0010:kasan_check_range+0x1ac/0x290 mm/kasan/generic.c:189
Code: 4c 89 d5 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b <41> 5e 41 5f 5d c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7
RSP: 0018:ffffc900001e0b40 EFLAGS: 00000097
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffffffff816bd18a
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001e0bc0
RBP: 0000000000000004 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffffffff9224e500
R13: 1ffff9200003c178 R14: fffff5200003c179 R15: 1ffffffff2449ca1
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fae81f8df98 CR3: 000000005ce43000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:542 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x14a/0x370 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x63/0x380 lib/debugobjects.c:752
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:481
 __run_hrtimer kernel/time/hrtimer.c:1654 [inline]
 __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:synchronize_rcu+0x0/0x3f0 kernel/rcu/tree.c:3565
Code: 5e 41 5f e9 a2 00 e6 ff 5b 41 5c 41 5e 41 5f c3 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c d9 fe ff ff e8 d5 91 6e 00 e9 cf fe ff ff <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 40 01
RSP: 0018:ffffc90003cffb38 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff9200079ff70 RCX: ffffffff91f31103
RDX: 0000777d5631c801 RSI: ffffffff8b0c0f40 RDI: ffffffff8b5d5de0
RBP: ffffc90003cffc08 R08: ffffffff813db1cd R09: fffffbfff1d33896
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888077c57928
R13: 1ffff9200079ff6c R14: 0000000000000203 R15: ffffc90003cffb80
 lockdep_unregister_key+0x537/0x5e0 kernel/locking/lockdep.c:6355
 wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
 pwq_unbound_release_workfn+0x23d/0x290 kernel/workqueue.c:3738
 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:295
 </TASK>
task:kworker/u4:3    state:R  running task     stack:21792 pid:51    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 preempt_schedule_notrace+0xf8/0x140 kernel/sched/core.c:6820
 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 rcu_is_watching+0x76/0xb0 kernel/rcu/tree.c:722
 rcu_read_lock include/linux/rcupdate.h:792 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x107/0x610 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:295
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g41781 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:5241 [inline]
 __schedule+0x143f/0x4570 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:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 3718 Comm: kworker/u4:5 Not tainted 6.1.103-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1fb0/0x3460 kernel/smp.c:998
Code: 2f 44 89 ee 83 e6 01 31 ff e8 4c 40 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 d7 3c 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff
RSP: 0018:ffffc900041af5a0 EFLAGS: 00000293
RAX: ffffffff817f63eb RBX: 1ffff110173281b1 RCX: ffff888020733b80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900041af980 R08: ffffffff817f63b4 R09: fffffbfff20e7245
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b9940d88
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020003c80 CR3: 000000000d08e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1334 [inline]
 text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534
 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:205
 static_key_enable+0x16/0x20 kernel/jump_label.c:218
 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804
 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:295
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/09 13:01 linux-6.1.y 48d525b0e463 a83d9288 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in pwq_unbound_release_workfn
* Struck through repros no longer work on HEAD.