rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=8134/1/0x4000000000000000 softirq=25920/25920 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=18649, q=450 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5822 Comm: syz-executor Not tainted 6.13.0-rc3-syzkaller-00026-g59dbb9d81adf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x70 kernel/kcov.c:217 Code: cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 48 8b 15 b4 c4 69 7e <65> 8b 05 b5 c4 69 7e a9 00 01 ff 00 48 8b 34 24 74 1d f6 c4 01 74 RSP: 0018:ffffc90000007df8 EFLAGS: 00000002 RAX: 0000000080010001 RBX: ffff8880b862cb00 RCX: ffffffff818741ba RDX: ffff888030a5a440 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff88805bc3d340 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000002 R12: ffff8880b862ca00 R13: 0000000000000010 R14: ffff8880b862ca00 R15: ffffffff8940f490 FS: 000055558528f500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdd9c12dd8 CR3: 00000000212b4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <IRQ> enqueue_hrtimer+0x108/0x3c0 kernel/time/hrtimer.c:1079 __run_hrtimer kernel/time/hrtimer.c:1756 [inline] __hrtimer_run_queues+0x903/0xae0 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x392/0x8e0 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10f/0x400 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 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline] RIP: 0010:path_init+0x96b/0x1a40 fs/namei.c:2554 Code: 64 ff 48 8b 75 08 48 89 df e8 41 45 64 ff 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 0f a2 87 ff 48 85 db 5a 0f 85 df 0c 00 00 <e8> 90 9f 87 ff 48 8b 45 a0 0f b6 00 38 45 98 7c 08 84 c0 0f 85 01 RSP: 0018:ffffc900032879e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff82128150 RDX: ffff888030a5a440 RSI: ffffffff8212815b RDI: ffffffff82129d03 RBP: ffffc90003287a88 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff8de15700 R13: 0000000000000000 R14: ffffc90003287b40 R15: ffff888032d42b00 path_lookupat+0x33/0x770 fs/namei.c:2624 filename_lookup+0x221/0x5f0 fs/namei.c:2663 vfs_statx+0xf8/0x1c0 fs/stat.c:344 vfs_fstatat+0x7b/0xf0 fs/stat.c:366 __do_sys_newfstatat+0xa2/0x130 fs/stat.c:530 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde9298453a Code: 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 0b 00 00 00 66 2e 0f 1f 84 00 00 00 00 00 90 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 RSP: 002b:00007ffdd9c13588 EFLAGS: 00000286 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde9298453a RDX: 00007ffdd9c135b0 RSI: 00007ffdd9c13640 RDI: 00000000ffffff9c RBP: 00007ffdd9c13640 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffdd9c146c0 R13: 00007fde92a0180c R14: 00007ffdd9c14700 R15: 000000000000006a </TASK> rcu: rcu_preempt kthread starved for 10475 jiffies! g18649 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:27600 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5369 [inline] __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6848 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 2995 Comm: kworker/u8:8 Not tainted 6.13.0-rc3-syzkaller-00026-g59dbb9d81adf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x458/0x1300 kernel/smp.c:884 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 aa 0d 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 a7 0c 00 00 8b 43 08 31 RSP: 0018:ffffc9000c8f7998 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b86469c0 RCX: ffffffff818e06bc RDX: ffff888030a58000 RSI: ffffffff818e0696 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170c8d39 R13: 0000000000000001 R14: ffff8880b86469c8 R15: ffff8880b873fe40 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b302feff8 CR3: 000000000df7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> </IRQ> <TASK> on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1051 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2114 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_flush arch/x86/kernel/alternative.c:2512 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:920 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:849 [inline] toggle_allocation_gate+0xfc/0x260 mm/kfence/core.c:841 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK>