rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9763/1:b..l rcu: (detected by 0, t=10502 jiffies, g=69213, q=263 ncpus=2) task:syz-executor state:R running task stack:21160 pid:9763 tgid:9763 ppid:9745 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:unwind_next_frame+0x180c/0x2390 arch/x86/kernel/unwind_orc.c:665 Code: 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 39 06 4c 8b 7c 24 48 48 8b 7c 24 70 0f 85 54 01 00 00 48 8b 44 24 58 80 3c 28 00 <74> 05 e8 0d 2f b1 00 4d 8b 66 38 49 8d 7e 08 48 89 f8 48 c1 e8 03 RSP: 0018:ffffc9000b9bf9b8 EFLAGS: 00000246 RAX: 1ffff92001737f58 RBX: ffffffff90d70b01 RCX: 0000000000000001 RDX: ffffc9000b9bfac8 RSI: dffffc0000000000 RDI: ffffc9000b9bfac0 RBP: dffffc0000000000 R08: ffffc9000b9bff48 R09: ffffc9000b9bfad8 R10: dffffc0000000000 R11: fffff52001737f5d R12: ffffc9000b9bff48 R13: ffffc9000b9bfad8 R14: ffffc9000b9bfa88 R15: ffffffff81728af5 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2907 [inline] __do_sys_mkdirat fs/namei.c:4425 [inline] __se_sys_mkdirat fs/namei.c:4423 [inline] __x64_sys_mkdirat+0x7a/0xa0 fs/namei.c:4423 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: 0033:0x7f423978d197 RSP: 002b:00007ffe04e8ddb8 EFLAGS: 00000206 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007ffe04e8de10 RCX: 00007f423978d197 RDX: 00000000000001ff RSI: 00007ffe04e8de10 RDI: 00000000ffffff9c RBP: 00007ffe04e8ddfc R08: 0000000000000005 R09: 00007ffe04e8db55 R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000000b7 R13: 00000000000927c0 R14: 00000000000d49d3 R15: 00007ffe04e8de50 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g69213 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=68438 rcu: rcu_preempt kthread starved for 10502 jiffies! g69213 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:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13210 Comm: syz.9.1492 Not tainted 6.16.0-rc3-syzkaller-00346-gafa9a6f4f574 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_preemption_disabled+0x3a/0x120 lib/smp_processor_id.c:55 Code: 35 07 48 89 44 24 08 65 8b 05 26 ee 35 07 65 8b 0d 1b ee 35 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d fb ed 35 07 48 3b 4c 24 08 <0f> 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d e9 cc 2e a9 f5 cc RSP: 0018:ffffc90000a081c0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000002 RCX: c39e55d64fa69900 RDX: 0000000000000004 RSI: ffffffff8db6ee41 RDI: ffffffff8be28cc0 RBP: ffff888025616590 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014102c R12: 0000000000000004 R13: 0000000000000004 R14: ffffffff99c90bc8 R15: ffff888025615a00 FS: 00007f3b136796c0(0000) GS:ffff888125d50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555e0ec608 CR3: 000000006067d000 CR4: 0000000000350ef0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline] lock_release+0x27a/0x3e0 kernel/locking/lockdep.c:5894 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x70/0x110 kernel/locking/spinlock.c:194 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline] debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:490 __run_hrtimer kernel/time/hrtimer.c:1729 [inline] __hrtimer_run_queues+0x2b0/0xc60 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+0x10b/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+0x52/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:memset+0xf/0x20 arch/x86/lib/memset_64.S:38 Code: 44 88 1f e9 0e 24 a9 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 e9 e2 23 a9 f5 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a08690 EFLAGS: 00000202 RAX: 1ffff92000141000 RBX: ffffc90000a087a0 RCX: 000000000000000f RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90000a087b9 RBP: dffffc0000000000 R08: ffffc90000a087c7 R09: ffffc90000a087b8 R10: dffffc0000000000 R11: fffff520001410f9 R12: ffffc90000a08e40 R13: ffffc90000a087b8 R14: ffffc90000a08768 R15: ffffc90000a087b0 unwind_next_frame+0xc98/0x2390 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 security_task_free+0xa4/0x1b0 security/security.c:3181 __put_task_struct+0xfd/0x460 kernel/fork.c:739 put_task_struct include/linux/sched/task.h:145 [inline] delayed_put_task_struct+0x11f/0x2f0 kernel/exit.c:230 rcu_do_batch kernel/rcu/tree.c:2576 [inline] rcu_core+0xca8/0x1710 kernel/rcu/tree.c:2832 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:_raw_spin_lock_irq+0x25/0xf0 kernel/locking/spinlock.c:169 Code: 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 41 56 53 48 83 e4 e0 48 83 ec 60 48 89 fb 65 48 8b 05 e0 7c 33 07 48 89 44 24 50 <48> c7 04 24 b3 8a b5 41 48 c7 44 24 08 82 c7 9f 8d 48 c7 44 24 10 RSP: 0018:ffffc9000409f860 EFLAGS: 00000286 RAX: c39e55d64fa69900 RBX: ffffc9000409fae8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8be28ca0 RDI: ffffc9000409fae8 RBP: ffffc9000409f8f0 R08: ffffffff8fa104f7 R09: 1ffffffff1f4209e R10: dffffc0000000000 R11: fffffbfff1f4209f R12: ffff888025617188 R13: 7fffffffffffffff R14: ffffc9000409fae8 R15: dffffc0000000000 do_wait_for_common kernel/sched/completion.c:96 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2ca/0x5d0 kernel/sched/completion.c:148 rdmsr_safe_on_cpu+0x150/0x230 arch/x86/lib/msr-smp.c:181 msr_read+0x14d/0x250 arch/x86/kernel/msr.c:66 vfs_read+0x200/0x980 fs/read_write.c:570 ksys_read+0x145/0x250 fs/read_write.c:715 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: 0033:0x7f3b1278e929 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:00007f3b13679038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f3b129b5fa0 RCX: 00007f3b1278e929 RDX: 0000000000019000 RSI: 0000200000032680 RDI: 0000000000000005 RBP: 00007f3b12810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3b129b5fa0 R15: 00007ffd89e21518