syzbot

 sign-in | mailing list | source | docs
🐞 Open [570] 🐞 Fixed [32] 🐞 Invalid [301] ⬇ Missing Backports [45] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

INFO: rcu detected stall in sys_symlinkat (2)

Status: auto-obsoleted due to no activity on 2024/03/12 11:22
Reported-by: syzbot+77d829b80abd9534aa11@syzkaller.appspotmail.com
First crash: 156d, last: 156d
▶ ▼ Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_symlinkat (3) ext4 3 283d 336d 0/26 auto-obsoleted due to no activity on 2023/10/26 22:46
linux-5.15 INFO: rcu detected stall in sys_symlinkat 1 347d 347d 0/3 auto-obsoleted due to no activity on 2023/09/03 15:54
linux-6.1 INFO: rcu detected stall in sys_symlinkat (2) 1 131d 131d 0/3 auto-obsoleted due to no activity on 2024/04/06 00:16
upstream INFO: rcu detected stall in sys_symlinkat kvm 5 616d 716d 0/26 auto-obsoleted due to no activity on 2022/11/28 07:06
linux-6.1 INFO: rcu detected stall in sys_symlinkat 1 376d 376d 0/3 auto-obsoleted due to no activity on 2023/08/23 09:07
upstream INFO: rcu detected stall in sys_symlinkat (2) ext4 lsm 2 429d 522d 0/26 auto-obsoleted due to no activity on 2023/06/03 10:14
upstream INFO: rcu detected stall in sys_symlinkat (4) ext4 1 160d 160d 0/26 auto-obsoleted due to no activity on 2024/02/27 04:07
android-5-15 BUG: soft lockup in sys_symlinkat 9 4d03h 22d 0/2 premoderation: reported on 2024/04/15 06:45

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=0bd/1/0x4000000000000000 softirq=24593/24593 fqs=1 
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3901/1:b..l
	(detected by 1, t=10503 jiffies, g=34117, q=21)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8741 Comm: syz-executor.0 Not tainted 5.15.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
RIP: 0010:kasan_check_range+0x1/0x290 mm/kasan/generic.c:188
Code: 01 c6 48 89 c7 e8 8f 9b 52 08 31 c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc cc cc cc cc 55 <41> 57 41 56 53 b0 01 48 85 f6 0f 84 9a 01 00 00 48 89 fd 48 01 f5
RSP: 0018:ffffc90000007a50 EFLAGS: 00000046
RAX: 0000000000000022 RBX: ffff888024100b68 RCX: ffffffff8162918f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fbce1d0
RBP: 0000000000000889 R08: dffffc0000000000 R09: fffffbfff1f79c3b
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000003
R13: ffff888024100ae8 R14: 1ffff11004820171 R15: ffff888024100b88
FS:  0000555556213480(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4a9a231d00 CR3: 000000001b3f7000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 __lock_acquire+0xcef/0x1ff0 kernel/locking/lockdep.c:4982
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 advance_sched+0x47/0x940 net/sched/sch_taprio.c:716
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x598/0xcf0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
 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:stack_trace_consume_entry+0xed/0x270 kernel/stacktrace.c:93
Code: 00 00 00 00 00 fc ff df 48 8b 1b 45 8d 70 01 41 0f b6 04 17 84 c0 0f 85 2d 01 00 00 45 89 31 4a 8d 1c c3 48 89 d8 48 c1 e8 03 <80> 3c 10 00 74 1a 4d 89 cf 48 89 df 49 89 d6 49 89 f5 e8 6c 16 5c
RSP: 0018:ffffc900059af610 EFLAGS: 00000a02
RAX: 1ffff92000b35f02 RBX: ffffc900059af810 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff83c556fa RDI: ffffc900059af74c
RBP: ffffc900059af748 R08: 0000000000000004 R09: ffffc900059af750
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000b35ee9
R13: 1ffff92000b35ee9 R14: 0000000000000005 R15: 1ffff92000b35eea
 arch_stack_walk+0x101/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc+0x168/0x300 mm/slub.c:4407
 kmalloc include/linux/slab.h:596 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x26b/0x530 security/tomoyo/realpath.c:80
 tomoyo_path_perm+0x386/0x6b0 security/tomoyo/file.c:831
 tomoyo_path_symlink+0xda/0x110 security/tomoyo/tomoyo.c:199
 security_path_symlink+0xd9/0x130 security/security.c:1179
 do_symlinkat+0x129/0x600 fs/namei.c:4382
 __do_sys_symlinkat fs/namei.c:4404 [inline]
 __se_sys_symlinkat fs/namei.c:4401 [inline]
 __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4401
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f4a9a1ae267
Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 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:00007ffd1f8e94b8 EFLAGS: 00000206 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007ffd1f8e9580 RCX: 00007f4a9a1ae267
RDX: 00007f4a9a1fa526 RSI: 00000000ffffff9c RDI: 00007ffd1f8e9580
RBP: 0000000000000001 R08: 0000000000000017 R09: 00007ffd1f8e9207
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
 </TASK>
task:kworker/u4:7    state:R  running task     stack:21144 pid: 3901 ppid:     2 flags:0x00004000
Workqueue: netns cleanup_net
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:426
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 dc 5e 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc9000596f8e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000b2df28 RCX: 1ffff92000b2dec8
RDX: dffffc0000000000 RSI: ffffffff8a8b2000 RDI: ffffffff8ad87d40
RBP: ffffc9000596fa40 R08: dffffc0000000000 R09: fffffbfff1f79c19
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000b2df24
R13: dffffc0000000000 R14: ffffc9000596f940 R15: 0000000000000246
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:269
 rcu_read_lock include/linux/rcupdate.h:696 [inline]
 inet_twsk_purge+0x11e/0xa20 net/ipv4/inet_timewait_sock.c:268
 ops_exit_list net/core/net_namespace.c:174 [inline]
 cleanup_net+0x763/0xb60 net/core/net_namespace.c:596
 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>
rcu: rcu_preempt kthread starved for 10501 jiffies! g34117 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27000 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 1
CPU: 1 PID: 21 Comm: kworker/1:0 Not tainted 5.15.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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:1685 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
 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:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xa93/0xd90 kernel/smp.c:969
Code: 04 03 84 c0 0f 85 84 00 00 00 45 8b 7d 00 44 89 fe 83 e6 01 31 ff e8 7c c6 0b 00 41 83 e7 01 75 07 e8 11 c3 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00
RSP: 0018:ffffc90000db78a0 EFLAGS: 00000293
RAX: ffffffff817462a4 RBX: 1ffff110173483c1 RCX: ffff8880129f9dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000db79e0 R08: ffffffff81746274 R09: fffffbfff1f79c1a
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: ffff8880b9a41e08 R14: ffff8880b9b3a780 R15: 0000000000000001
 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 (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/03 11:21 linux-5.15.y 9b91d36ba301 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_symlinkat
* Struck through repros no longer work on HEAD.