rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=aa24/1/0x4000000000000000 softirq=84714/84716 fqs=0 (detected by 1, t=10506 jiffies, g=131677, q=129 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22977 Comm: syz-executor.5 Not tainted 6.1.0-rc6-syzkaller-00012-g4312098baf37 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__lock_acquire+0xb38/0x56d0 kernel/locking/lockdep.c:5050 Code: 04 80 49 8d 3c c7 e8 87 75 8a 08 85 c0 74 c8 4c 8b 64 24 70 44 8b 7c 24 78 48 c7 c2 48 d3 51 8e 48 b8 00 00 00 00 00 fc ff df <48> c1 ea 03 0f b6 14 02 48 c7 c0 48 d3 51 8e 83 e0 07 83 c0 03 38 RSP: 0018:ffffc90000007bb8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 8cda6a2d213aba94 RCX: ffffffff8162b326 RDX: ffffffff8e51d348 RSI: ffff8880263a0a50 RDI: ffff8880263a0b11 RBP: 0000000000000040 R08: 0000000000000000 R09: ffffffff910f3a4f R10: fffffbfff221e749 R11: 0000000000000000 R12: ffff8880263a0af0 R13: ffff8880263a0000 R14: 0000000000000004 R15: 0000000000000001 FS: 00007fbbe72b1700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002008d000 CR3: 000000009c952000 CR4: 0000000000350ef0 Call Trace: lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x266/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x180/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__might_resched+0x4/0x2d0 kernel/sched/core.c:9863 Code: c7 43 08 00 00 00 00 48 8b 44 24 78 65 48 2b 04 25 28 00 00 00 75 07 48 83 ec 80 5b 5d c3 e8 03 0c 97 08 0f 1f 00 f3 0f 1e fa <41> 56 41 55 41 54 41 89 f4 be ff ff ff ff 55 48 89 fd 48 c7 c7 e0 RSP: 0018:ffffc90016aaf880 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff88807ec4c000 RCX: ffffc90004891000 RDX: 0000000000000000 RSI: 0000000000001753 RDI: ffffffff8a621a20 RBP: ffff888086d98cb8 R08: 0000000000000007 R09: fffffffffffff000 R10: ffff8880991c6e70 R11: 0000000000092080 R12: ffff8880991c6e70 R13: ffff8880991c6e70 R14: 1ffff92002d55f17 R15: ffff88807ec4e000 __ext4_mark_inode_dirty+0xeb/0x940 fs/ext4/inode.c:5971 ext4_dirty_inode+0xd8/0x110 fs/ext4/inode.c:6010 __mark_inode_dirty+0x247/0x11e0 fs/fs-writeback.c:2400 mark_inode_dirty include/linux/fs.h:2467 [inline] generic_write_end+0x354/0x440 fs/buffer.c:2184 ext4_da_write_end+0x1f5/0xa30 fs/ext4/inode.c:3096 generic_perform_write+0x316/0x570 mm/filemap.c:3764 ext4_buffered_write_iter+0x15b/0x460 fs/ext4/file.c:285 ext4_file_write_iter+0x8bc/0x16e0 fs/ext4/file.c:700 call_write_iter include/linux/fs.h:2191 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x9ed/0xdd0 fs/read_write.c:584 ksys_write+0x12b/0x250 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fbbe648c0d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbbe72b1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbbe65abf80 RCX: 00007fbbe648c0d9 RDX: 00000000087fd008 RSI: 0000000020000040 RDI: 0000000000000004 RBP: 00007fbbe64e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcfa23d38f R14: 00007fbbe72b1300 R15: 0000000000022000 rcu: rcu_preempt kthread starved for 10506 jiffies! g131677 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27944 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5209 [inline] __schedule+0xae9/0x53f0 kernel/sched/core.c:6521 schedule+0xde/0x1b0 kernel/sched/core.c:6597 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1660 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1859 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 4126 Comm: kworker/u4:28 Not tainted 6.1.0-rc6-syzkaller-00012-g4312098baf37 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline] RIP: 0010:smp_call_function_many_cond+0x43f/0x10a0 kernel/smp.c:987 Code: e6 e8 95 f7 0a 00 45 85 e4 74 48 48 8b 04 24 49 89 c5 83 e0 07 49 c1 ed 03 49 89 c4 4d 01 fd 41 83 c4 03 e8 c3 fa 0a 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 4e 0a 00 00 8b 43 08 31 RSP: 0018:ffffc90006137970 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9a43420 RCX: 0000000000000000 RDX: ffff88807dd70000 RSI: ffffffff81751f4d RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed1017348685 R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2aadd0e280 CR3: 000000000c28e000 CR4: 0000000000350ee0 Call Trace: on_each_cpu_cond_mask+0x5a/0xa0 kernel/smp.c:1155 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1311 [inline] text_poke_bp_batch+0x22e/0x6b0 arch/x86/kernel/alternative.c:1502 text_poke_flush arch/x86/kernel/alternative.c:1670 [inline] text_poke_flush arch/x86/kernel/alternative.c:1667 [inline] text_poke_finish+0x1a/0x30 arch/x86/kernel/alternative.c:1677 arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x32f/0x410 kernel/jump_label.c:801 static_key_enable_cpuslocked+0x1b5/0x270 kernel/jump_label.c:177 static_key_enable+0x1a/0x20 kernel/jump_label.c:190 toggle_allocation_gate mm/kfence/core.c:800 [inline] toggle_allocation_gate+0x104/0x390 mm/kfence/core.c:792 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289 worker_thread+0x669/0x1090 kernel/workqueue.c:2436 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306