syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (3 ticks this GP) idle=3c4c/1/0x4000000000000000 softirq=18260/18260 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=12221, q=404 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6109 Comm: syz.0.22 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:137 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x29f/0x2c0 mm/kasan/generic.c:189
Code: f3 49 83 c3 05 eb 07 4d 01 f3 49 83 c3 06 4d 89 dc 4d 85 db 0f 84 44 ff ff ff 4d 01 d1 4d 39 cc 75 11 41 83 e0 07 45 0f be 09 <45> 39 c8 0f 8c 2b ff ff ff 0f b6 d2 e8 a0 ef ff ff 34 01 e9 1c ff
RSP: 0018:ffffc90000a08ae8 EFLAGS: 00000006
RAX: 00000000ffffff01 RBX: ffffffffffffffff RCX: ffffffff819e00e1
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000a08b60
RBP: ffffc90000a08bd0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200014116c R12: fffff5200014116c
R13: ffffffff99d527c0 R14: fffff5200014116d R15: 1ffff9200014116c
FS:  00007f17a98396c0(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000600 CR3: 000000006fc8c000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x121/0x290 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162
 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline]
 debug_activate kernel/time/hrtimer.c:484 [inline]
 enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088
 __run_hrtimer kernel/time/hrtimer.c:1778 [inline]
 __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:86 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x89/0x2c0 mm/kasan/generic.c:189
Code: ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 <4d> 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00
RSP: 0018:ffffc90003037910 EFLAGS: 00000283
RAX: ffffffff8b758901 RBX: dffffc0000000001 RCX: ffffffff8b7589f6
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8c935a00
RBP: ffffffff8c935a08 R08: ffffffff8c935a07 R09: 1ffffffff1926b40
R10: dffffc0000000000 R11: fffffbfff1926b40 R12: 0000000000000001
R13: ffffc90003037aa0 R14: fffffbfff1926b41 R15: 1ffffffff1926b40
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 vsnprintf+0x386/0xf00 lib/vsprintf.c:2878
 dynamic_dname+0xfc/0x1b0 fs/d_path.c:308
 tomoyo_realpath_from_path+0x170/0x5d0 security/tomoyo/realpath.c:258
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_number_perm+0x1e8/0x5a0 security/tomoyo/file.c:723
 security_file_ioctl+0xcb/0x2d0 security/security.c:2943
 __do_sys_ioctl fs/ioctl.c:592 [inline]
 __se_sys_ioctl+0x47/0x170 fs/ioctl.c:584
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f17a898ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f17a9839038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f17a8bb5fa0 RCX: 00007f17a898ebe9
RDX: 0000200000000600 RSI: 0000000000008933 RDI: 0000000000000003
RBP: 00007f17a8a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f17a8bb6038 R14: 00007f17a8bb5fa0 R15: 00007ffccbbdc5c8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g12221 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=3961
rcu: rcu_preempt kthread starved for 10502 jiffies! g12221 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:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>