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INFO: rcu detected stall in security_file_open (3)

Status: upstream: reported on 2025/08/25 12:48
Reported-by: syzbot+d0ed163317f17bfd41ed@syzkaller.appspotmail.com
First crash: 111d, last: 12h07m
▶ ▼ Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in security_file_open (5) tomoyo 1 4 1481d 1591d 0/29 closed as invalid on 2022/02/08 09:50
upstream INFO: rcu detected stall in security_file_open (3) afs 1 C done done 2 1902d 1901d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in security_file_open mm 1 5 2202d 2204d 0/29 closed as invalid on 2019/12/04 14:04
linux-6.6 INFO: rcu detected stall in security_file_open 1 2 14d 23d 0/2 upstream: reported on 2025/11/22 02:38
upstream INFO: rcu detected stall in security_file_open (2) mm 1 2 2168d 2168d 0/29 closed as invalid on 2020/01/08 05:23
linux-6.1 INFO: rcu detected stall in security_file_open 1 1 817d 817d 0/3 auto-obsoleted due to no activity on 2023/12/28 22:15
linux-5.15 INFO: rcu detected stall in security_file_open (2) origin:upstream 1 syz 3 3d08h 306d 0/3 upstream: reported syz repro on 2025/02/11 10:29
upstream INFO: rcu detected stall in security_file_open (4) tomoyo 1 1 1700d 1700d 0/29 auto-closed as invalid on 2021/06/18 10:54
linux-6.1 INFO: rcu detected stall in security_file_open (2) 1 1 474d 474d 0/3 auto-obsoleted due to no activity on 2024/12/06 07:18
linux-5.15 INFO: rcu detected stall in security_file_open 1 3 426d 513d 0/3 auto-obsoleted due to no activity on 2025/01/22 08:07
upstream INFO: rcu detected stall in security_file_open (6) mm 1 C error 295 1d15h 901d 0/29 closed as dup on 2023/06/27 10:07

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=2fcc/1/0x4000000000000000 softirq=25560/25561 fqs=0
	(detected by 0, t=10505 jiffies, g=27957, q=155 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6904 Comm: syz.2.439 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x8c/0x100 kernel/locking/spinlock.c:194
Code: c7 18 48 8b 75 08 e8 53 06 49 f7 4c 89 f7 e8 ab cb 49 f7 f7 c3 00 02 00 00 74 05 e8 6e be 6c f7 48 c7 44 24 20 00 00 00 00 9c <8f> 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01
RSP: 0018:ffffc900001e0bf8 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000802 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff96ca0690
RBP: ffffc900001e0c80 R08: dffffc0000000000 R09: fffffbfff2d940d3
R10: fffffbfff2d940d3 R11: 1ffffffff2d940d2 R12: dffffc0000000000
R13: 0000000000000002 R14: ffffffff96ca0690 R15: 1ffff9200003c180
FS:  00007f32587b26c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f32587aff70 CR3: 000000005b127000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 debug_object_activate+0x2d7/0x490 lib/debugobjects.c:716
 debug_hrtimer_activate kernel/time/hrtimer.c:448 [inline]
 debug_activate kernel/time/hrtimer.c:503 [inline]
 enqueue_hrtimer+0x30/0x3f0 kernel/time/hrtimer.c:1105
 __run_hrtimer kernel/time/hrtimer.c:1764 [inline]
 __hrtimer_run_queues+0x68e/0xd60 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 c0 f7 c1 08 e8 eb b6 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000ecd6d58 EFLAGS: 00000282
RAX: 2a77baefe863cf00 RBX: 0000000000000000 RCX: 2a77baefe863cf00
RDX: dffffc0000000000 RSI: ffffffff8a6c0600 RDI: ffffffff8abef920
RBP: ffffc9000ecd6db0 R08: dffffc0000000000 R09: ffffed10171e7559
R10: ffffed10171e7559 R11: 1ffff110171e7558 R12: ffff8880290e8000
R13: dffffc0000000000 R14: ffff888057a35940 R15: ffff8880b8f3b590
 context_switch kernel/sched/core.c:5247 [inline]
 __schedule+0x10f4/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 unwind_next_frame+0x1892/0x20b0 arch/x86/kernel/unwind_orc.c:629
 __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:717
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700
 tomoyo_realpath_from_path+0x599/0x5d0 security/tomoyo/realpath.c:286
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x1aa/0x380 security/tomoyo/file.c:771
 security_file_open+0x5e/0xa0 security/security.c:1681
 do_dentry_open+0x305/0x10d0 fs/open.c:869
 do_open fs/namei.c:3634 [inline]
 path_openat+0x25c6/0x2e70 fs/namei.c:3791
 do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
 do_sys_openat2+0x142/0x490 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f325798df90
Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 69 95 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 bc 95 02 00 8b 44
RSP: 002b:00007f32587afef0 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f325798df90
RDX: 0000000000000002 RSI: 00007f3257a13c6c RDI: 00000000ffffff9c
RBP: 00007f3257a13c6c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000036 R14: 0000200000000000 R15: 00007ffcc391a8a8
 </TASK>
rcu: rcu_preempt kthread starved for 10505 jiffies! g27957 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:27904 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 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: 6870 Comm: kworker/u4:37 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0xe7b/0x1270 kernel/smp.c:998
Code: 00 00 00 41 8b 1f 89 de 83 e6 01 31 ff e8 5d d9 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 e9 d5 0a 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 ce d5 0a
RSP: 0018:ffffc9000e8af800 EFLAGS: 00000293
RAX: ffffffff81760a02 RBX: dffffc0000000000 RCX: ffff888023d79dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000e8af960 R08: dffffc0000000000 R09: fffffbfff2119049
R10: fffffbfff2119049 R11: 1ffffffff2119048 R12: 1ffff110171e81c9
R13: ffff8880b8e3bb80 R14: 0000000000000001 R15: ffff8880b8f40e48
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f23023ce420 CR3: 000000000c68e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1165
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1574 [inline]
 text_poke_bp_batch+0x2b0/0x7d0 arch/x86/kernel/alternative.c:1774
 text_poke_flush arch/x86/kernel/alternative.c:1965 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1972
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x11f/0x240 kernel/jump_label.c:207
 static_key_enable+0x16/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xb4/0x430 mm/kfence/core.c:805
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/14 19:27 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in security_file_open
2025/12/12 02:02 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in security_file_open
2025/11/09 07:02 linux-6.1.y f6e38ae624cf 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in security_file_open
2025/08/25 12:47 linux-6.1.y 0bc96de781b4 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in security_file_open
* Struck through repros no longer work on HEAD.