syzbot

 sign-in | mailing list | source | docs
🐞 Open [1515]
≡ Subsystems
🐞 Fixed [6635]
🐞 Invalid [17004]
⬇ Missing Backports [212]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

INFO: rcu detected stall in batadv_tt_purge (4)

Status: auto-obsoleted due to no activity on 2025/05/07 20:48
Subsystems: batman
[Documentation on labels]
First crash: 245d, last: 245d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in batadv_tt_purge 1 1 404d 404d 0/3 auto-obsoleted due to no activity on 2024/12/09 22:28
linux-5.15 INFO: rcu detected stall in batadv_tt_purge (2) 1 1 59d 59d 0/3 upstream: reported on 2025/08/12 03:39
upstream INFO: rcu detected stall in batadv_tt_purge (2) batman 1 C done inconclusive 3 968d 1537d 0/29 auto-obsoleted due to no activity on 2023/06/14 13:09
upstream INFO: rcu detected stall in batadv_tt_purge cgroups mm 1 1 2102d 2101d 0/29 closed as invalid on 2020/01/09 08:13
linux-6.1 INFO: rcu detected stall in batadv_tt_purge 1 6 492d 564d 0/3 auto-obsoleted due to no activity on 2024/09/12 14:42
upstream INFO: rcu detected stall in batadv_tt_purge (3) batman 1 1 690d 674d 0/29 auto-obsoleted due to no activity on 2024/02/17 16:44
upstream BUG: soft lockup in batadv_tt_purge batman 1 1 474d 472d 0/29 auto-obsoleted due to no activity on 2024/09/20 21:14

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P15605/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=61329, q=319 ncpus=2)
task:syz-executor    state:R  running task     stack:24096 pid:15605 tgid:15605 ppid:15598  task_flags:0x400140 flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5377 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6764
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6943
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_pte_range mm/memory.c:1201 [inline]
 copy_pmd_range mm/memory.c:1262 [inline]
 copy_pud_range mm/memory.c:1299 [inline]
 copy_p4d_range mm/memory.c:1323 [inline]
 copy_page_range+0x1e7f/0x5690 mm/memory.c:1421
 dup_mmap kernel/fork.c:748 [inline]
 dup_mm kernel/fork.c:1700 [inline]
 copy_mm kernel/fork.c:1752 [inline]
 copy_process+0x7ccb/0x8c50 kernel/fork.c:2403
 kernel_clone+0xfd/0x960 kernel/fork.c:2815
 __do_sys_clone+0xba/0x100 kernel/fork.c:2958
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8a75583653
RSP: 002b:00007ffdd2009e98 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8a75583653
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000555586ea37d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 00000000000c2199 R15: 00007ffdd200a030
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g61329 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=46576
rcu: rcu_preempt kthread starved for 10502 jiffies! g61329 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26128 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5377 [inline]
 __schedule+0xf43/0x5890 kernel/sched/core.c:6764
 __schedule_loop kernel/sched/core.c:6841 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6856
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2024
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2226
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 9188 Comm: kworker/u8:14 Not tainted 6.14.0-rc1-syzkaller-00034-g92514ef226f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Workqueue: bat_events batadv_tt_purge
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:154 [inline]
RIP: 0010:lock_release+0x3d0/0x6f0 kernel/locking/lockdep.c:5875
Code: 20 f0 6c 8b e8 d1 bc bf 09 b8 ff ff ff ff 65 0f c1 05 7c eb 6b 7e 83 f8 01 0f 85 fe 01 00 00 9c 58 f6 c4 02 0f 85 e9 01 00 00 <48> f7 04 24 00 02 00 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df 48
RSP: 0018:ffffc90000a18ca8 EFLAGS: 00000046
RAX: 0000000000000046 RBX: 1ffff92000143197 RCX: ffffc90000a18cf8
RDX: 1ffff110070aca6c RSI: ffffffff8b6cf020 RDI: ffffffff8bd34c80
RBP: b05ef340f351284c R08: 0000000000000000 R09: fffffbfff20c4502
R10: ffffffff90622817 R11: 0000000000000002 R12: 0000000000000002
R13: 0000000000000003 R14: ffff888038565368 R15: ffff888038564880
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7bfd6940 CR3: 0000000086464000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
 _raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 advance_sched+0x611/0xc60 net/sched/sch_taprio.c:981
 __run_hrtimer kernel/time/hrtimer.c:1801 [inline]
 __hrtimer_run_queues+0x20a/0xae0 kernel/time/hrtimer.c:1865
 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1927
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x10f/0x400 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x9f/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:write_comp_data+0x42/0x90 kernel/kcov.c:246
Code: a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 2c 16 00 00 85 c0 74 4f 8b 82 08 16 00 00 <83> f8 03 75 44 48 8b 82 10 16 00 00 8b 92 0c 16 00 00 48 8b 38 48
RSP: 0018:ffffc9000b1cfb30 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000400 RCX: ffffffff8b27adb0
RDX: ffff888038564880 RSI: 0000000000000046 RDI: 0000000000000004
RBP: ffff88805e5bbe80 R08: 0000000000000004 R09: 0000000000000046
R10: 0000000000000400 R11: 0000000000000002 R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88802f378228 R15: 0000000000000046
 batadv_tt_global_purge net/batman-adv/translation-table.c:2226 [inline]
 batadv_tt_purge+0x280/0xb90 net/batman-adv/translation-table.c:3510
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/06 20:44 upstream 92514ef226f5 577d049b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in batadv_tt_purge
* Struck through repros no longer work on HEAD.