syzbot


INFO: rcu detected stall in sys_futex

Status: upstream: reported on 2023/07/05 11:35
Reported-by: syzbot+97f2ac670e5e7a3b48e4@syzkaller.appspotmail.com
First crash: 355d, last: 5d04h
Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_futex (7) kernel 33 1d03h 6h14m 0/27 upstream: reported on 2024/06/24 16:48
upstream INFO: rcu detected stall in sys_futex (3) kernel 959 1629d 1678d 0/27 auto-closed as invalid on 2020/03/08 12:44
upstream INFO: rcu detected stall in sys_futex (2) kernel 6 1797d 1941d 0/27 auto-closed as invalid on 2019/10/25 14:11
upstream INFO: rcu detected stall in sys_futex (4) kernel 1 878d 878d 0/27 closed as invalid on 2022/02/08 10:00
linux-5.15 INFO: rcu detected stall in sys_futex (2) 2 12d 19d 0/3 upstream: reported on 2024/06/05 16:49
upstream INFO: rcu detected stall in sys_futex kernel 1 2003d 2003d 0/27 closed as invalid on 2018/12/31 04:10
linux-5.15 INFO: rcu detected stall in sys_futex 4 175d 349d 0/3 auto-obsoleted due to no activity on 2024/04/10 17:08
upstream INFO: rcu detected stall in sys_futex (5) kernel 12 609d 854d 0/27 auto-obsoleted due to no activity on 2023/02/12 18:33
upstream INFO: rcu detected stall in sys_futex (6) kernel 10 177d 413d 0/27 auto-obsoleted due to no activity on 2024/03/29 00:57

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3578/1:b..l
	(detected by 1, t=10502 jiffies, g=6605, q=29 ncpus=2)
task:syz-executor.2  state:R  running task     stack:20088 pid:3578  ppid:3564   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 unwind_next_frame+0x1a55/0x2220 arch/x86/kernel/unwind_orc.c:629
 __unwind_start+0x59d/0x720 arch/x86/kernel/unwind_orc.c:717
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xdb/0x140 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 save_stack+0xf6/0x1e0 mm/page_owner.c:127
 __reset_page_owner+0x52/0x1a0 mm/page_owner.c:148
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1440 [inline]
 free_pcp_prepare mm/page_alloc.c:1490 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3499
 release_pages+0x2836/0x2b40 mm/swap.c:1055
 __pagevec_release+0x80/0xf0 mm/swap.c:1075
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x865/0x2390 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x265/0xa60 mm/shmem.c:1171
 evict+0x2a4/0x620 fs/inode.c:666
 __dentry_kill+0x436/0x650 fs/dcache.c:607
 dentry_kill+0xbb/0x290
 dput+0xfb/0x1d0 fs/dcache.c:914
 __fput+0x5e4/0x890 fs/file_table.c:328
 task_work_run+0x246/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f822ae7e257
RSP: 002b:00007ffdf248e168 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f822ae7e257
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf248e220
RBP: 00007ffdf248e220 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf248f2d0
R13: 00007f822aed96c6 R14: 000000000000fa9e R15: 0000000000000006
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10535 jiffies! g6605 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=3897
rcu: rcu_preempt kthread starved for 10536 jiffies! g6605 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I 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: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:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3710 Comm: syz-executor.3 Not tainted 6.1.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:hlock_class kernel/locking/lockdep.c:223 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4724 [inline]
RIP: 0010:__lock_acquire+0x51b/0x1f80 kernel/locking/lockdep.c:4999
Code: 8a df 5e 10 00 0f 84 6d 05 00 00 31 db 48 81 c3 b8 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 5e 12 00 00 0f b6 2b <41> 0f b6 04 17 84 c0 0f 85 72 12 00 00 41 8b 1e 81 e3 ff 1f 00 00
RSP: 0018:ffffc90000007be0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff90197b58 RCX: ffffffff816a7175
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff9049d228
RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff2093a46
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888023fa0ad8
R13: ffff888023fa0000 R14: ffff888023fa0b00 R15: 1ffff110047f4160
FS:  00007fd7067ca6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32a25000 CR3: 0000000014318000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 hrtimer_interrupt+0xf7/0x980 kernel/time/hrtimer.c:1793
 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:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124
Code: 2e 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 7b 23 36 09 e8 06 1e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc900046778a8 EFLAGS: 00000286
RAX: 184b855cd667d700 RBX: ffff888023fa1df4 RCX: ffffffff91c95103
RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff888023fa15f8
RBP: ffffc900046778f0 R08: dffffc0000000000 R09: ffffed1017307541
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888023fa0000
R13: 1ffff110173076eb R14: ffff8880b983aa00 R15: ffff8880b983b758
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1435/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 futex_wait_queue+0x149/0x1d0 kernel/futex/waitwake.c:355
 futex_wait+0x203/0x5c0 kernel/futex/waitwake.c:656
 do_futex+0x3b5/0x490 kernel/futex/syscalls.c:106
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd705a7cf29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 01 48
RSP: 002b:00007fd7067ca178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fd705bb41f8 RCX: 00007fd705a7cf29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd705bb41f8
RBP: 00007fd705bb41f0 R08: 00007fd7067ca6c0 R09: 00007fd7067ca6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd705bb41fc
R13: 000000000000006e R14: 00007ffd66757720 R15: 00007ffd66757808
 </TASK>
sched: RT throttling activated

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/19 18:49 linux-6.1.y eb44d83053d6 41b7e219 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/11 01:38 linux-6.1.y 88690811da69 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/08 12:33 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/07 10:14 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/06 13:57 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/05/09 12:07 linux-6.1.y 909ba1f1b414 05079661 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/05/05 09:10 linux-6.1.y 909ba1f1b414 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_futex
2024/03/28 15:11 linux-6.1.y e5cd595e23c1 e91187ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/01/09 19:35 linux-6.1.y 38fb82ecd144 4807fb37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2023/10/04 13:29 linux-6.1.y d23900f974e0 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2023/07/14 08:34 linux-6.1.y 61fd484b2cf6 d624500f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2023/07/05 11:34 linux-6.1.y 0f4ac6b4c5f0 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
* Struck through repros no longer work on HEAD.