rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13687/1:b..l rcu: (detected by 1, t=10506 jiffies, g=79261, q=356 ncpus=2) task:syz.1.1894 state:R running task stack:25160 pid:13687 tgid:13682 ppid:5607 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:68 Code: ff ff 48 c7 c7 58 c2 ab 8b e8 69 ba be 00 e9 1e fa ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90005bdeee0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff9184d052 RDX: ffffc90005bdf301 RSI: ffffc90005bdf398 RDI: ffffc90005bdf398 RBP: ffffc90005bdf398 R08: 0000000000000001 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000016a8e R12: ffffc90005bdefa8 R13: ffffc90005bdef58 R14: ffffc90005bdf3c8 R15: ffffc90005bdef8c deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline] unwind_next_frame+0x1561/0x2090 arch/x86/kernel/unwind_orc.c:677 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5296 [inline] __kmalloc_node_noprof+0x307/0x850 mm/slub.c:5302 kmalloc_node_noprof include/linux/slab.h:1081 [inline] alloc_slab_obj_exts+0xae/0x270 mm/slub.c:2171 account_slab mm/slub.c:3421 [inline] allocate_slab mm/slub.c:3498 [inline] new_slab+0x4eb/0x6c0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] push_stack+0x73/0x380 kernel/bpf/verifier.c:1719 check_cond_jmp_op kernel/bpf/verifier.c:16443 [inline] do_check_insn kernel/bpf/verifier.c:17655 [inline] do_check kernel/bpf/verifier.c:17804 [inline] do_check_common+0x39ff/0xd580 kernel/bpf/verifier.c:18819 do_check_main kernel/bpf/verifier.c:18902 [inline] bpf_check+0xa8a4/0xabe0 kernel/bpf/verifier.c:20073 bpf_prog_load+0x1c0f/0x2b30 kernel/bpf/syscall.c:3082 __sys_bpf+0x223a/0x4b90 kernel/bpf/syscall.c:6274 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline] __se_sys_bpf kernel/bpf/syscall.c:6385 [inline] __x64_sys_bpf+0x7b/0xc0 kernel/bpf/syscall.c:6385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x860 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd01539ce59 RSP: 002b:00007fd0161c6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fd015616090 RCX: 00007fd01539ce59 RDX: 0000000000000094 RSI: 0000200000000840 RDI: 0000000000000005 RBP: 00007fd015432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd015616128 R14: 00007fd015616090 R15: 00007fff65060a08 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g79261 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=46797 rcu: rcu_preempt kthread starved for 10506 jiffies! g79261 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:28216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1295/0x67a0 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7283 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13693 Comm: syz.5.1898 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x40/0x310 kernel/locking/lockdep.c:5879 Code: 2d 3d cf 26 12 48 89 6c 24 10 48 89 f5 0f 1f 44 00 00 65 8b 05 55 cf 26 12 83 f8 07 0f 87 63 02 00 00 48 0f a3 05 60 57 f3 0e <0f> 82 fa 01 00 00 44 8b 05 e7 8a f3 0e 45 85 c0 0f 84 48 01 00 00 RSP: 0018:ffffc90000007e28 EFLAGS: 00000097 RAX: 0000000000000000 RBX: ffff8880b84284d8 RCX: ffffffff81f47924 RDX: ffff8880348a0000 RSI: ffffffff81f47e93 RDI: ffff8880b84284d8 RBP: ffffffff81f47e93 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880207ac300 R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b8428650 FS: 00007f7d1033d6c0(0000) GS:ffff88812436a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e00ce20 CR3: 0000000033ca9000 CR4: 00000000003526f0 DR0: 0000000000000009 DR1: 00000000000000c9 DR2: 00000000000000f3 DR3: 00000000000000c0 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:198 __run_hrtimer kernel/time/hrtimer.c:1926 [inline] __hrtimer_run_queues+0x383/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 a6 4f 56 f6 48 89 df e8 7e 9f 56 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 a5 6b 46 f6 65 8b 05 fe 1e 7d 08 85 c0 74 16 5b RSP: 0018:ffffc9000581fd78 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffffff9b1b1118 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8df2430b RDI: ffffffff8c1c4400 RBP: 0000000000000202 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000007700000000 R12: 1ffff92000b03fb6 R13: 000000000d1f25e8 R14: 000000000d1f25e8 R15: 0000000000000000 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:571 [inline] do_settimeofday64+0x326/0x4d0 kernel/time/timekeeping.c:1584 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1108 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1108 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x860 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7d0f39ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7d1033d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f7d0f615fa0 RCX: 00007f7d0f39ce59 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000000 RBP: 00007f7d0f432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7d0f616038 R14: 00007f7d0f615fa0 R15: 00007ffc0a528af8