rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=1954/1/0x4000000000000000 softirq=40637/40637 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=41969, q=379 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11769 Comm: syz.1.1971 Not tainted 6.13.0-rc7-syzkaller-00209-g9528d418de4d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:lock_is_held_type+0x20/0x190 kernel/locking/lockdep.c:5906 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 ff ff ff ff 83 3d 54 ab 57 04 00 0f 84 00 01 00 00 65 8b 05 87 RSP: 0018:ffffc90000007cf8 EFLAGS: 00000082 RAX: f36d485e2b4fdb00 RBX: 0000000000000001 RCX: ffff888025689e00 RDX: ffff888025689e00 RSI: 00000000ffffffff RDI: ffff8880b862c898 RBP: ffffc90000007ea0 R08: ffffffff818cc87e R09: 0000000000000000 R10: ffff888034cbe348 R11: ffffed1006997c6b R12: 1ffff110170c593b R13: dffffc0000000000 R14: ffff888078ec2340 R15: ffff8880b862c980 FS: 00007f4a8c8446c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3b1029 CR3: 000000002078a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0x2d9/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d f4 2b 8e 0c 48 89 de 5b e9 43 71 58 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 80 d4 03 00 65 8b 15 00 6d 64 7e 81 e2 00 01 ff 00 RSP: 0018:ffffc90002fc7858 EFLAGS: 00000202 RAX: ffffffff81e83446 RBX: 0000000000000001 RCX: ffff888025689e00 RDX: ffff888025689e00 RSI: ffffffff8c5f01c0 RDI: ffffffff8c5f0180 RBP: ffffc90002fc7970 R08: ffffffff81e83434 R09: 1ffff110051af2cc R10: dffffc0000000000 R11: ffffed10051af2cd R12: 0000000000010000 R13: dffffc0000000000 R14: ffffc90002fc7900 R15: ffffea00014fdf00 rcu_read_unlock include/linux/rcupdate.h:878 [inline] pte_unmap include/linux/pgtable.h:136 [inline] follow_page_pte+0xe86/0x1ca0 mm/gup.c:944 follow_pmd_mask mm/gup.c:978 [inline] follow_pud_mask mm/gup.c:1030 [inline] follow_p4d_mask mm/gup.c:1047 [inline] follow_page_mask mm/gup.c:1090 [inline] __get_user_pages+0xb90/0x49e0 mm/gup.c:1492 populate_vma_page_range+0x264/0x330 mm/gup.c:1932 __mm_populate+0x27a/0x460 mm/gup.c:2035 mm_populate include/linux/mm.h:3397 [inline] vm_mmap_pgoff+0x2c3/0x3d0 mm/util.c:580 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a8b985d29 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:00007f4a8c844038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f4a8bb75fa0 RCX: 00007f4a8b985d29 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f4a8ba01b08 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4a8bb75fa0 R15: 00007ffc69afb548 rcu: rcu_preempt kthread starved for 10490 jiffies! g41969 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:26008 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/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: 1 UID: 0 PID: 11723 Comm: kworker/u8:12 Not tainted 6.13.0-rc7-syzkaller-00209-g9528d418de4d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x19f3/0x2c60 kernel/smp.c:884 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 c6 e6 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 71 e2 0b 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 55 e2 RSP: 0018:ffffc900056876e0 EFLAGS: 00000293 RAX: ffffffff8193851b RBX: 1ffff110170c8c65 RCX: ffff88807b555a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900056878e0 R08: ffffffff819384ea R09: 1ffffffff284ef10 R10: dffffc0000000000 R11: fffffbfff284ef11 R12: dffffc0000000000 R13: ffff8880b8646328 R14: ffff8880b873f940 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c336eb4 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 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+0x352/0xb30 arch/x86/kernel/alternative.c:2324 text_poke_flush arch/x86/kernel/alternative.c:2515 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2522 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xbc/0x260 mm/kfence/core.c:849 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244