rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=be94/1/0x4000000000000000 softirq=88546/88546 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=83789, q=430 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 20927 Comm: syz.3.4097 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:299 Code: 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 RSP: 0018:ffffc90000a08d60 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff88805e356000 RCX: ffffffff89377853 RDX: ffffed100bc6ac2c RSI: 000000005e16d801 RDI: 0000000000000000 RBP: ffff88805e16d801 R08: 0000000000000001 R09: ffffed100bc6ac2b R10: ffff88805e35615f R11: 0000000000000000 R12: 183e84616fa116d8 R13: 183e84616fa116d8 R14: 0000000000000002 R15: ffff88805e16fc10 FS: 000055558fd21500(0000) GS:ffff888124b54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa39afd0d58 CR3: 0000000024ba6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __netif_schedule+0x3a/0x2f0 net/core/dev.c:3349 advance_sched+0x6c1/0xc80 net/sched/sch_taprio.c:986 __run_hrtimer kernel/time/hrtimer.c:1801 [inline] __hrtimer_run_queues+0x1ff/0xad0 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1927 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:instrument_atomic_read_write include/linux/instrumented.h:96 [inline] RIP: 0010:atomic_inc include/linux/atomic/atomic-instrumented.h:435 [inline] RIP: 0010:mt_validate_nulls+0x379/0x9e0 lib/maple_tree.c:7521 Code: 00 00 00 00 00 fc ff df e9 ac 01 00 00 e8 9f 7f 65 f6 be 04 00 00 00 48 c7 c7 40 4d e8 9a e8 9e 17 c9 f6 f0 ff 05 87 d6 92 0f 82 7f 65 f6 be 04 00 00 00 48 c7 c7 00 4d e8 9a e8 81 17 c9 f6 RSP: 0018:ffffc90003d8f858 EFLAGS: 00000207 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff8b5576b2 RDX: fffffbfff35d09a8 RSI: 0000000000000004 RDI: ffffffff9ae84d40 RBP: ffff88806408d4d8 R08: 0000000000000001 R09: fffffbfff35d09a8 R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000001 R14: 0000000000000300 R15: 0000000000000000 mt_validate+0x30d8/0x4210 lib/maple_tree.c:7571 validate_mm+0xb0/0x570 mm/vma.c:584 mmap_region+0x1e9/0x3f0 mm/vma.c:2546 do_mmap+0xd8e/0x11b0 mm/mmap.c:561 vm_mmap_pgoff+0x281/0x450 mm/util.c:578 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:607 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 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: 0033:0x7fa39a18d1a3 Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7 RSP: 002b:00007ffc8eaadc18 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fa3987f76c0 RCX: 00007fa39a18d1a3 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffc8eaadd70 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10498 jiffies! g83789 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28856 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5367 [inline] __schedule+0x1129/0x5c00 kernel/sched/core.c:6748 __schedule_loop kernel/sched/core.c:6825 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6840 schedule_timeout+0x123/0x280 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+0x3a4/0x760 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 8260 Comm: kworker/u8:12 Not tainted 6.14.0-syzkaller-01103-g2df0c02dab82 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4a5/0x1290 kernel/smp.c:885 Code: 89 ee e8 4e 1e 0c 00 85 ed 74 48 48 8b 44 24 20 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 fd 22 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 de 0b 00 00 8b 43 08 31 RSP: 0018:ffffc9000c777938 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b853f500 RCX: ffffffff81aed369 RDX: ffff88802f41a440 RSI: ffffffff81aed343 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170a7ea1 R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b843b000 FS: 0000000000000000(0000) GS:ffff888124a54000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3ce7e7 CR3: 000000000e182000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2455 [inline] text_poke_bp_batch+0x220/0x760 arch/x86/kernel/alternative.c:2665 text_poke_flush arch/x86/kernel/alternative.c:2856 [inline] text_poke_flush arch/x86/kernel/alternative.c:2853 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2863 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:850 [inline] toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c1/0xef0 kernel/workqueue.c:3400 kthread+0x3a4/0x760 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