syzbot

 sign-in | mailing list | source | docs
🐞 Open [560] 🐞 Fixed [32] 🐞 Invalid [300] ⬇ Missing Backports [45] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

INFO: rcu detected stall in dput (2)

Status: upstream: reported on 2024/03/15 21:30
Reported-by: syzbot+8070d18dbf272904961e@syzkaller.appspotmail.com
First crash: 47d, last: 39d
▶ ▼ Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in dput (4) kvm C error error 2 874d 1233d 0/26 closed as invalid on 2022/02/08 10:37
upstream INFO: rcu detected stall in dput (3) kernel 1 1576d 1576d 0/26 closed as invalid on 2020/01/09 08:13
upstream INFO: rcu detected stall in dput (8) mm C done 16 5d20h 122d 0/26 upstream: reported C repro on 2023/12/31 19:35
linux-5.15 INFO: rcu detected stall in dput 2 246d 286d 0/3 auto-obsoleted due to no activity on 2023/12/08 00:28
upstream INFO: rcu detected stall in dput (6) fs 2 548d 607d 0/26 auto-obsoleted due to no activity on 2023/01/16 04:13
upstream INFO: rcu detected stall in dput (5) fs 1 744d 744d 0/26 auto-closed as invalid on 2022/07/18 12:41
linux-6.1 INFO: rcu detected stall in dput 1 294d 294d 0/3 auto-obsoleted due to no activity on 2023/10/20 22:44
upstream INFO: rcu detected stall in dput fs 1 1611d 1611d 0/26 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in dput (2) kernel 2 1576d 1576d 0/26 closed as invalid on 2020/01/08 05:33

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=687/1/0x4000000000000000 softirq=41474/41476 fqs=1 
	(detected by 0, t=10502 jiffies, g=54097, q=224)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13447 Comm: syz-executor.4 Not tainted 5.15.152-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3681 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3701 [inline]
RIP: 0010:validate_chain+0x167/0x5930 kernel/locking/lockdep.c:3756
Code: e2 03 00 00 48 b8 eb 83 b5 80 46 86 c8 61 49 0f af c6 48 c1 e8 2f 48 8d 1c c5 40 f0 a8 8f 48 89 d8 48 c1 e8 03 48 89 44 24 50 <42> 80 3c 20 00 74 08 48 89 df e8 ea b0 66 00 48 89 5c 24 20 48 8b
RSP: 0018:ffffc90000dd07c0 EFLAGS: 00000802
RAX: 1ffffffff1f594d3 RBX: ffffffff8faca698 RCX: ffffffff816344f2
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fbcf0c8
RBP: ffffc90000dd0a70 R08: dffffc0000000000 R09: fffffbfff1f79e1a
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888022aba8d0 R14: 4b21b045db16ba9e R15: ffff888022aba8d0
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde298fe988 CR3: 00000001552e2000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x662/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:unwind_next_frame+0x16e/0x1fa0 arch/x86/kernel/unwind_orc.c:448
Code: 6d 00 48 8b 44 24 28 80 3c 10 00 48 8b 5c 24 08 74 12 48 89 df e8 62 8d 91 00 48 ba 00 00 00 00 00 fc ff df 4c 03 2b 49 ff cd <48> 89 6c 24 68 4c 89 64 24 60 0f 84 00 01 00 00 48 c7 c0 00 00 00
RSP: 0018:ffffc90003146d28 EFLAGS: 00000286
RAX: 1ffff92000628dc5 RBX: ffffc90003146e28 RCX: ffffffff8a255200
RDX: dffffc0000000000 RSI: ffffffff81bf4707 RDI: ffffffff8138683b
RBP: ffffc90003146e15 R08: 0000000000000001 R09: ffffc90003146ed0
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000628dc2
R13: ffffffff81bf4706 R14: ffffffff81bf4707 R15: ffffc90003146de0
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 save_stack+0xf6/0x1e0 mm/page_owner.c:119
 __reset_page_owner+0x52/0x180 mm/page_owner.c:140
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 mm/swap.c:963
 __pagevec_release+0x80/0xf0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 truncate_inode_pages_range+0x48b/0x1290 mm/truncate.c:329
 ext4_evict_inode+0x2ae/0x1100 fs/ext4/inode.c:224
 evict+0x2a4/0x620 fs/inode.c:587
 __dentry_kill+0x436/0x650 fs/dcache.c:582
 dentry_kill+0xbb/0x290
 dput+0xd8/0x1a0 fs/dcache.c:889
 __fput+0x5ec/0x890 fs/file_table.c:288
 task_work_run+0x129/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:872
 do_group_exit+0x144/0x310 kernel/exit.c:994
 get_signal+0xc66/0x14e0 kernel/signal.c:2889
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:314
 exc_general_protection+0x358/0x4f0 arch/x86/kernel/traps.c:562
 asm_exc_general_protection+0x22/0x30 arch/x86/include/asm/idtentry.h:562
RIP: 0033:0x7fde297cedb1
Code: Unable to access opcode bytes at RIP 0x7fde297ced87.
RSP: 002b:0000000020000190 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fde298fcf80 RCX: 00007fde297ceda9
RDX: 0000000020000000 RSI: 0000000020000190 RDI: 0000000000300000
RBP: 00007fde2981b47a R08: 00000000200001c0 R09: 00000000200001c0
R10: 0000000020000040 R11: 0000000000000206 R12: 0000000000000000
R13: 000000000000000b R14: 00007fde298fcf80 R15: 00007ffcde9ea1a8
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g54097 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:26936 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
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884
 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:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 3539 Comm: kworker/0:3 Not tainted 5.15.152-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: events bpf_prog_free_deferred
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1788
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x60 kernel/kcov.c:197
Code: e4 35 82 7e 65 8b 15 e5 35 82 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 <83> fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14
RSP: 0018:ffffc90002f77898 EFLAGS: 00000246
RAX: ffffffff81746eb4 RBX: 1ffff110173680b1 RCX: ffff8880220e9dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002f779e0 R08: ffffffff81746e84 R09: fffffbfff1f79e1a
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: ffff8880b9b40588 R14: ffff8880b9a3b380 R15: 0000000000000001
 csd_lock_wait kernel/smp.c:440 [inline]
 smp_call_function_many_cond+0xab4/0xd90 kernel/smp.c:969
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1135
 __purge_vmap_area_lazy+0x294/0x1740 mm/vmalloc.c:1683
 _vm_unmap_aliases+0x453/0x4e0 mm/vmalloc.c:2107
 vm_remove_mappings mm/vmalloc.c:2584 [inline]
 __vunmap+0x72e/0xa20 mm/vmalloc.c:2611
 bpf_jit_binary_free kernel/bpf/core.c:914 [inline]
 bpf_jit_free+0x92/0x180 kernel/bpf/core.c:927
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/23 20:19 linux-5.15.y b95c01af2113 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in dput
2024/03/15 21:29 linux-5.15.y b95c01af2113 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in dput
* Struck through repros no longer work on HEAD.