rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=5224/1/0x4000000000000000 softirq=163344/163363 fqs=1 rcu: (detected by 0, t=10502 jiffies, g=157953, q=417 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3855 Comm: syz.8.6868 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0x28/0x3c40 kernel/locking/lockdep.c:5077 Code: 90 90 41 57 41 56 41 89 f6 41 55 41 54 49 89 fc 55 89 d5 53 44 89 cb 48 81 ec f0 00 00 00 48 8b 84 24 28 01 00 00 44 89 04 24 <48> c7 84 24 90 00 00 00 b3 8a b5 41 48 c7 84 24 98 00 00 00 5f e2 RSP: 0018:ffffc90000a18be8 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b872ca18 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff905f5c17 R11: 0000000000000001 R12: ffff8880b872ca18 R13: ffff8880b872ca18 R14: 0000000000000000 R15: 0000000000000000 FS: 0000555583809500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c800ff8 CR3: 00000000509da000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __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:1743 [inline] __hrtimer_run_queues+0x2be/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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_lock_parent_ip include/linux/ftrace.h:999 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:5829 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:5826 [inline] RIP: 0010:preempt_count_add+0x76/0x150 kernel/sched/core.c:5854 Code: a6 7e 3c f4 77 6b 65 8b 05 3f ad a6 7e 25 ff ff ff 7f 39 c3 74 07 5b 5d c3 cc cc cc cc 48 8b 5c 24 10 48 89 df e8 1a 97 0e 00 <85> c0 75 38 65 48 8b 2d 0e ad a6 7e 48 8d bd c8 14 00 00 48 b8 00 RSP: 0018:ffffc90003a3fad0 EFLAGS: 00000283 RAX: 0000000000000000 RBX: ffffffff816a2e10 RCX: 1ffffffff3508914 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff816a2e10 RBP: ffffffff905f8f30 R08: 0000000000000000 R09: ffffed100549c99a R10: ffff88802a4e4cd7 R11: 0000000000000001 R12: ffff88802a4e4cd0 R13: 1ffff92000747f60 R14: ffff88802a4e4d30 R15: 00007feb78b10000 __up_read+0x110/0x760 kernel/locking/rwsem.c:1343 anon_vma_unlock_read include/linux/rmap.h:146 [inline] validate_mm+0x270/0x530 mm/vma.c:615 mmap_region+0x165/0x320 mm/mmap.c:1353 do_mmap+0xc00/0xfc0 mm/mmap.c:496 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:588 ksys_mmap_pgoff+0x7d/0x5c0 mm/mmap.c:542 __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/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb7897e853 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:00007ffff8841028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007feb76ff76c0 RCX: 00007feb7897e853 RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffff8841180 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10495 jiffies! g157953 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:27616 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 30309 Comm: kworker/u8:5 Not tainted 6.12.0-syzkaller-09073-g9f16d5e6f220 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x70 kernel/kcov.c:217 Code: 00 48 8b 34 24 74 1d f6 c4 01 74 43 a9 00 00 0f 00 75 3c a9 00 00 f0 00 75 35 8b 82 1c 16 00 00 85 c0 74 2b 8b 82 f8 15 00 00 <83> f8 02 75 20 48 8b 8a 00 16 00 00 8b 92 fc 15 00 00 48 8b 01 48 RSP: 0018:ffffc90004b57990 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880b8744a40 RCX: ffffffff8182a93c RDX: ffff88802fdf0000 RSI: ffffffff8182a916 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10170e8949 R13: 0000000000000001 R14: ffff8880b8744a48 R15: ffff8880b863fe40 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbccda94321 CR3: 000000000df7e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rep_nop arch/x86/include/asm/vdso/processor.h:13 [inline] cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x456/0x1300 kernel/smp.c:884 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+0x659/0x760 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