rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=d89c/1/0x4000000000000000 softirq=52150/52150 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11632/1:b..l rcu: (detected by 1, t=10502 jiffies, g=36325, q=65 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11643 Comm: syz.3.1378 Not tainted 6.15.0-rc5-syzkaller-00136-g9c69f8884904 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:check_preemption_disabled+0x8/0xe0 lib/smp_processor_id.c:14 Code: 37 08 85 c0 74 04 90 0f 0b 90 e9 53 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 54 55 53 48 83 ec 08 <65> 8b 1d 85 24 37 08 65 8b 05 7a 24 37 08 a9 ff ff ff 7f 74 0f 48 RSP: 0018:ffffc90000007ce0 EFLAGS: 00000082 RAX: ffff88805443a440 RBX: ffff888029569300 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8dcd2703 RDI: ffffffff8bf48320 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fe7648586c0(0000) GS:ffff8881249e1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c28689f CR3: 0000000036148000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:467 [inline] lock_acquire kernel/locking/lockdep.c:5865 [inline] lock_acquire+0x140/0x350 kernel/locking/lockdep.c:5823 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xd9/0xc80 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 e6 9e 28 f6 48 89 df e8 8e f2 28 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 5e 19 f6 65 8b 05 1e 94 34 08 85 c0 74 16 5b RSP: 0018:ffffc90000b27ca8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffff8880b8427840 RCX: 0000000000000007 RDX: 0000000000000000 RSI: ffffffff8dbe181f RDI: ffffffff8bf48320 RBP: 0000000000000283 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff9084f117 R11: 0000000000000000 R12: 0000000000000000 R13: 0000007bfd42f080 R14: dffffc0000000000 R15: ffff8880b8427840 clock_was_set+0x599/0x870 kernel/time/hrtimer.c:972 do_settimeofday64+0x304/0x4b0 kernel/time/timekeeping.c:1381 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1140 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1124 [inline] __x64_sys_clock_settime+0x1be/0x2a0 kernel/time/posix-timers.c:1124 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: 0033:0x7fe76398e969 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:00007fe764858038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007fe763bb6240 RCX: 00007fe76398e969 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000000 RBP: 00007fe763a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fe763bb6240 R15: 00007ffe4f19a698 task:syz.5.1377 state:R running task stack:26360 pid:11632 tgid:11630 ppid:6174 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:debug_lockdep_rcu_enabled+0xe/0x40 kernel/rcu/update.c:320 Code: 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 8b 05 66 3b 18 05 85 c0 74 20 <8b> 05 10 6a 18 05 85 c0 74 16 65 48 8b 05 68 39 37 08 8b 80 ec 0a RSP: 0018:ffffc90002f472a0 EFLAGS: 00000202 RAX: 0000000000000002 RBX: ffffc90002f47720 RCX: ffffc90002f48001 RDX: ffffc90002f47728 RSI: ffffc90002f47710 RDI: ffffc90002f47328 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 00000000000145c2 R12: ffffc90002f47368 R13: ffffc90002f47318 R14: ffffc90002f47720 R15: ffffc90002f4734c rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3de/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 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4203 alloc_buffer_head+0x21/0x160 fs/buffer.c:3032 folio_alloc_buffers+0x2bd/0x830 fs/buffer.c:937 create_empty_buffers+0x36/0x480 fs/buffer.c:1697 folio_create_buffers+0x109/0x150 fs/buffer.c:1808 __block_write_begin_int+0x320/0x16d0 fs/buffer.c:2132 iomap_write_begin+0x5de/0x1680 fs/iomap/buffered-io.c:825 iomap_write_iter fs/iomap/buffered-io.c:952 [inline] iomap_file_buffered_write+0x43b/0xcb0 fs/iomap/buffered-io.c:1033 blkdev_buffered_write block/fops.c:690 [inline] blkdev_write_iter+0x56f/0xdf0 block/fops.c:755 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x5ba/0x1180 fs/read_write.c:684 ksys_write+0x12a/0x240 fs/read_write.c:736 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: 0033:0x7f15f8b8e969 RSP: 002b:00007f15f9940038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f15f8db6080 RCX: 00007f15f8b8e969 RDX: 00000000fffffd2c RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f15f8c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f15f8db6080 R15: 00007fff73da6a78 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g36325 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=32331 rcu: rcu_preempt kthread starved for 10502 jiffies! g36325 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:28024 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