rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 ticks this GP) idle=e9b4/1/0x4000000000000000 softirq=67713/67717 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P17401/3:b..l rcu: (detected by 1, t=10506 jiffies, g=91249, q=113 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 17416 Comm: syz.8.3354 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:115 [inline] RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2151 [inline] RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1296 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] RIP: 0010:do_raw_spin_lock+0x12e/0x2c0 kernel/locking/spinlock_debug.c:115 Code: 00 48 89 df be 04 00 00 00 e8 9e 8b 74 00 48 8d 7c 24 40 be 04 00 00 00 e8 8f 8b 74 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 d9 00 00 00 65 8b 1d 81 68 9b 7e 48 b9 00 00 00 00 00 fc ff RSP: 0018:ffffc90000007ba0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff88801a2e52e8 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007be0 RBP: ffffc90000007c60 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000000f7c R12: ffff88801a2e52f8 R13: ffff88801a2e52f0 R14: 1ffff1100345ca5f R15: 1ffff1100345ca5e FS: 00007f4b679556c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c375c43 CR3: 000000002377d000 CR4: 00000000003506f0 Call Trace: spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xc5/0xc80 net/sched/sch_taprio.c:940 __run_hrtimer kernel/time/hrtimer.c:1755 [inline] __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1819 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc900049c6f30 EFLAGS: 00000206 RAX: 81fa481c934f6e00 RBX: ffff88802ab93c00 RCX: 81fa481c934f6e00 RDX: ffffc900102d9000 RSI: ffffffff8aaacc20 RDI: ffffffff8afc70c0 RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff21b4aa0 R10: dffffc0000000000 R11: fffffbfff21b4aa1 R12: 0000000000000001 R13: 0000000000000246 R14: ffffffff8cd2fc20 R15: ffff88802ab94708 lookup_page_ext mm/page_ext.c:240 [inline] page_ext_get+0x193/0x2b0 mm/page_ext.c:509 __set_page_owner+0x28/0x60 mm/page_owner.c:194 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 __folio_alloc+0x10/0x20 mm/page_alloc.c:4489 vma_alloc_folio+0x47a/0x8f0 mm/mempolicy.c:2242 shmem_alloc_folio+0x179/0x230 mm/shmem.c:1680 shmem_alloc_and_acct_folio+0x189/0x630 mm/shmem.c:1705 shmem_get_folio_gfp+0xcde/0x2ac0 mm/shmem.c:2042 shmem_fault+0x1b6/0x7f0 mm/shmem.c:2249 __do_fault+0x13b/0x4e0 mm/memory.c:4243 do_read_fault mm/memory.c:4616 [inline] do_fault mm/memory.c:4753 [inline] do_pte_missing mm/memory.c:3688 [inline] handle_pte_fault mm/memory.c:5025 [inline] __handle_mm_fault mm/memory.c:5166 [inline] handle_mm_fault+0x3886/0x4920 mm/memory.c:5331 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3328 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4b66b8eba9 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:00007f4b67955038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f4b66dd5fa0 RCX: 00007f4b66b8eba9 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f4b66c11e19 R08: ffffffffffffffff R09: 0000000094173000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b66dd6038 R14: 00007f4b66dd5fa0 R15: 00007ffd6da3aca8 task:syz.7.3349 state:R running task stack:25672 pid:17401 ppid:14953 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0x1069/0x1630 mm/filemap.c:3655 do_fault_around mm/memory.c:4573 [inline] do_read_fault mm/memory.c:4606 [inline] do_fault mm/memory.c:4753 [inline] do_pte_missing mm/memory.c:3688 [inline] handle_pte_fault mm/memory.c:5025 [inline] __handle_mm_fault mm/memory.c:5166 [inline] handle_mm_fault+0x379b/0x4920 mm/memory.c:5331 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3328 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7efd5d18eba9 RSP: 002b:00007efd5e108038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007efd5d3d5fa0 RCX: 00007efd5d18eba9 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007efd5d211e19 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efd5d3d6038 R14: 00007efd5d3d5fa0 R15: 00007fff0ade2178 rcu: rcu_preempt kthread starved for 10506 jiffies! g91249 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:27496 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 17413 Comm: syz.1.3352 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0xde4/0x1130 kernel/smp.c:855 Code: 89 ee 83 e6 01 31 ff e8 da d6 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 d3 0a 00 eb 38 f3 90 42 0f b6 04 2b <84> c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 f9 d2 0a 00 eb e4 44 RSP: 0018:ffffc9000465f900 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110171c87d9 RCX: ffff88802a605a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000465fa80 R08: ffffffff90da5507 R09: 1ffffffff21b4aa0 R10: dffffc0000000000 R11: fffffbfff21b4aa1 R12: ffff8880b8e43ec8 R13: dffffc0000000000 R14: ffff8880b8f3d588 R15: 0000000000000000 FS: 000055555ad0b500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2e2c2d CR3: 0000000057bc8000 CR4: 00000000003506e0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2222 [inline] text_poke_bp_batch+0x318/0x930 arch/x86/kernel/alternative.c:2432 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:237 static_key_disable+0x1a/0x20 kernel/jump_label.c:245 tracepoint_remove_func kernel/tracepoint.c:417 [inline] tracepoint_probe_unregister+0x6ad/0x930 kernel/tracepoint.c:551 bpf_raw_tp_link_release+0x63/0x90 kernel/bpf/syscall.c:3375 bpf_link_free+0x131/0x310 kernel/bpf/syscall.c:2918 bpf_link_put_direct kernel/bpf/syscall.c:2958 [inline] bpf_link_release+0x6e/0x80 kernel/bpf/syscall.c:2965 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8ee8f8eba9 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:00007ffd667c3b98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000010b3ae RCX: 00007f8ee8f8eba9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f8ee91d7da0 R08: 0000000000000001 R09: 00000007667c3e8f R10: 0000001b2ec20000 R11: 0000000000000246 R12: 00007f8ee91d5fac R13: 00007f8ee91d5fa0 R14: ffffffffffffffff R15: 00007ffd667c3cb0