rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=cd0c/1/0x4000000000000000 softirq=22995/22995 fqs=0 rcu: (detected by 1, t=10502 jiffies, g=13089, q=943 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6696 Comm: syz-executor Not tainted 6.14.0-syzkaller-12456-gacc4d5ff0b61 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0x5a4/0x1ba0 kernel/locking/lockdep.c:5230 Code: 5b 02 00 00 48 63 c5 4c 89 fe 48 8d 04 80 49 8d 3c c4 e8 3f 54 d9 09 85 c0 74 d9 8b 4c 24 30 44 0f b7 64 24 38 48 8b 6c 24 40 <44> 8b 1d 85 55 ee 0e 45 85 db 75 29 44 8b 54 24 08 45 85 d2 0f 85 RSP: 0018:ffffc90000007bc0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff888067eb0bb8 RCX: 00000000c032add5 RDX: 0000000000000000 RSI: ffff888067eb0bb8 RDI: 000000005a08aec3 RBP: ffff888067eb0af0 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000000 R11: ffffffff9ace4de8 R12: 0000000000000000 R13: 0000000000000002 R14: ffff888067eb0000 R15: 0000000000000000 FS: 00005555674ec500(0000) GS:ffff8881249bb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2efd6d CR3: 000000006a636000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_activate+0x14c/0x4c0 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:486 [inline] enqueue_hrtimer+0x23/0x3b0 kernel/time/hrtimer.c:1090 __run_hrtimer kernel/time/hrtimer.c:1808 [inline] __hrtimer_run_queues+0x8ff/0xad0 kernel/time/hrtimer.c:1855 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1917 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870 Code: 31 0e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 02 07 ee 0e 0f 82 74 02 00 00 8b 35 7a 36 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 d9 30 0e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc9000321f360 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c15c0 RCX: 000000009d994fd0 RDX: 0000000000000000 RSI: ffffffff8dbc5e57 RDI: ffffffff8bf458a0 RBP: 0000000000000002 R08: e2ccb7f23d347ab8 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4331 [inline] __kmalloc_node_noprof+0x21e/0x500 mm/slub.c:4337 kmalloc_array_node_noprof include/linux/slab.h:1020 [inline] alloc_slab_obj_exts+0x41/0xa0 mm/slub.c:1987 account_slab mm/slub.c:2586 [inline] allocate_slab mm/slub.c:2641 [inline] new_slab+0x284/0x330 mm/slub.c:2676 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3862 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3952 __slab_alloc_node mm/slub.c:4027 [inline] slab_alloc_node mm/slub.c:4188 [inline] kmem_cache_alloc_noprof+0xef/0x3b0 mm/slub.c:4207 vm_area_dup+0x25/0x760 kernel/fork.c:488 dup_mmap kernel/fork.c:672 [inline] dup_mm kernel/fork.c:1734 [inline] copy_mm kernel/fork.c:1786 [inline] copy_process+0x7f67/0x91a0 kernel/fork.c:2429 kernel_clone+0xfc/0x960 kernel/fork.c:2844 __do_sys_clone+0xce/0x120 kernel/fork.c:2987 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7febb73839d3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd164ebc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007febb73839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555674ec7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000019194 R15: 00007ffd164ebe10 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=4624 rcu: rcu_preempt kthread starved for 10502 jiffies! g13089 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:27688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245