rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=ab04/1/0x4000000000000000 softirq=12525/12526 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=8609, q=2835 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6063 Comm: syz-executor Not tainted 6.13.0-rc7-syzkaller-01160-g41c5d104f338 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:65 Code: 1e 3a f5 e8 e2 b8 3c f5 eb a8 e8 ab e0 ff ff 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 0f 1e fa 48 89 fe 48 c7 c7 20 b2 5f 8c e9 bd fe ff ff 66 2e 0f RSP: 0018:ffffc90000a18c20 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88802b8ebc00 RDX: ffff88802b8ebc00 RSI: ffff888020efc300 RDI: ffffffff8c0aaae0 RBP: 0000000000000004 R08: ffffffff89ced4fb R09: fffff5200014317c R10: dffffc0000000000 R11: fffff5200014317c R12: 0000000000000046 R13: ffff88802b8ebc00 R14: 00000000ffffffff R15: ffff888020efc300 FS: 000055557eb68500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f13fc776038 CR3: 000000007d26c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_is_held_type+0x101/0x190 kernel/locking/lockdep.c:5922 lock_is_held include/linux/lockdep.h:249 [inline] advance_sched+0x1c2/0xca0 net/sched/sch_taprio.c:929 __run_hrtimer kernel/time/hrtimer.c:1739 [inline] __hrtimer_run_queues+0x59b/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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 7a 2b 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90004f971e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920009f2e48 RCX: ffff88802b8ec6d8 RDX: dffffc0000000000 RSI: ffffffff8c0aaae0 RDI: ffffffff8c5fb220 RBP: ffffc90004f97338 R08: ffffffff942c1887 R09: 1ffffffff2858310 R10: dffffc0000000000 R11: fffffbfff2858311 R12: 1ffff920009f2e44 R13: dffffc0000000000 R14: ffffc90004f97240 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 page_table_check_set+0x4f/0x540 mm/page_table_check.c:114 __page_table_check_ptes_set+0x30f/0x410 mm/page_table_check.c:225 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline] set_ptes include/linux/pgtable.h:288 [inline] insert_page_into_pte_locked+0x5e7/0x6c0 mm/memory.c:2075 insert_page mm/memory.c:2093 [inline] vm_insert_page+0x4c1/0x710 mm/memory.c:2243 kcov_mmap+0xd7/0x140 kernel/kcov.c:506 call_mmap include/linux/fs.h:2183 [inline] mmap_file mm/internal.h:124 [inline] __mmap_new_file_vma mm/vma.c:2291 [inline] __mmap_new_vma mm/vma.c:2355 [inline] __mmap_region+0x224e/0x2d30 mm/vma.c:2456 mmap_region+0x226/0x2c0 mm/mmap.c:1352 do_mmap+0x97a/0x10d0 mm/mmap.c:500 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:575 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:546 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: 0033:0x7f13fc585d63 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:00007fff8689e458 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f13fc776038 RCX: 00007f13fc585d63 RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f13fbbff000 RBP: 00007f13fc776038 R08: 00000000000000d8 R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000008 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10498 jiffies! g8609 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:26264 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 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: 0 UID: 0 PID: 54 Comm: kworker/u8:3 Not tainted 6.13.0-rc7-syzkaller-01160-g41c5d104f338 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate 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 c0 8f 0c 48 89 de 5b e9 a3 fc 5a 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 c0 d5 03 00 65 8b 15 40 53 64 7e 81 e2 00 01 ff 00 RSP: 0018:ffffc90000be76d8 EFLAGS: 00000202 RAX: ffffffff8193a01b RBX: 1ffff110170e88e1 RCX: ffff8880232e5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000be78e0 R08: ffffffff81939fea R09: 1ffffffff2858310 R10: dffffc0000000000 R11: fffffbfff2858311 R12: dffffc0000000000 R13: ffff8880b8744708 R14: ffff8880b863fa80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560151f43ca3 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0x1a0b/0x2c60 kernel/smp.c:884 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