rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9692/1:b..l P9239/1:b..l rcu: (detected by 1, t=10502 jiffies, g=29309, q=1387912 ncpus=2) task:syz-executor state:R running task stack:23672 pid:9239 tgid:9239 ppid:9220 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7113 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x50c/0x20a0 arch/x86/kernel/unwind_orc.c:505 Code: e8 19 f1 ff ff 48 89 c1 48 85 c0 0f 84 05 fe ff ff 48 b8 00 00 00 00 00 fc ff df 4c 8d 79 05 4c 89 fa 48 c1 ea 03 0f b6 04 02 <4c> 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 32 14 00 00 0f b6 41 05 RSP: 0018:ffffc90003547470 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff913d8f78 RDX: 1ffffffff227b1ef RSI: 0000000000000000 RDI: ffffffff90b9cd2c RBP: ffffc90003547578 R08: ffffffff913d8f8a R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000061e4 R12: ffffc90003547580 R13: ffffc90003547530 R14: ffffc90003547565 R15: ffffffff913d8f7d __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4204 vm_area_dup+0x27/0x8d0 mm/vma_init.c:122 dup_mmap+0x877/0x21d0 mm/mmap.c:1784 dup_mm kernel/fork.c:1477 [inline] copy_mm kernel/fork.c:1529 [inline] copy_process+0x4081/0x7650 kernel/fork.c:2169 kernel_clone+0xfc/0x960 kernel/fork.c:2599 __do_sys_clone+0xce/0x120 kernel/fork.c:2742 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feaf4b85193 RSP: 002b:00007ffdb24714b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007feaf4b85193 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055558e5567d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000067683 R15: 00007ffdb2471650 task:syz-executor state:R running task stack:28712 pid:9692 tgid:9692 ppid:5834 task_flags:0x400040 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7113 irqentry_exit+0x36/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:873 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1155 [inline] RIP: 0010:unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 Code: 41 c7 45 00 00 00 00 00 31 ed e8 02 47 1d 0a 85 c0 0f 85 a7 06 00 00 48 c7 c7 80 4e 5c 8e 48 8d 35 00 00 00 00 e8 27 ad 2d 00 a2 62 37 00 e9 3d fc ff ff 49 81 ff 00 a0 25 92 72 0d 49 81 ff RSP: 0018:ffffc900051c7800 EFLAGS: 00000292 RAX: 0000000000000000 RBX: ffffc900051c7f58 RCX: ffffc900051c77c4 RDX: 0000000000000003 RSI: ffffffff8de0d05d RDI: ffffffff8c158f60 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000a87c0 R12: ffffc900051c78c0 R13: ffffc900051c7870 R14: ffffc900051c7f58 R15: ffffc900051c78a4 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_lru_noprof+0x1d0/0x3b0 mm/slub.c:4216 __d_alloc+0x31/0xaa0 fs/dcache.c:1690 d_alloc+0x4a/0x1e0 fs/dcache.c:1769 lookup_one_qstr_excl_raw.part.0+0x96/0x160 fs/namei.c:1685 lookup_one_qstr_excl_raw fs/namei.c:1677 [inline] lookup_one_qstr_excl+0x3e/0x120 fs/namei.c:1711 filename_create+0x1e7/0x4a0 fs/namei.c:4149 do_symlinkat+0xbe/0x310 fs/namei.c:4758 __do_sys_symlinkat fs/namei.c:4781 [inline] __se_sys_symlinkat fs/namei.c:4778 [inline] __x64_sys_symlinkat+0x93/0xc0 fs/namei.c:4778 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d0218dea7 RSP: 002b:00007ffe8b8efb68 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0d0218dea7 RDX: 00007f0d02212390 RSI: 00000000ffffff9c RDI: 00007ffe8b8efc00 RBP: 00007ffe8b8efbac R08: 0000000000000017 R09: 00007ffe8b8ef8b7 R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000d2 R13: 00000000000927c0 R14: 0000000000067217 R15: 00007ffe8b8efc00 rcu: rcu_preempt kthread starved for 10153 jiffies! g29309 f0x2 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x116a/0x5de0 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6883 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2256 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc5-syzkaller-00038-g733923397fd9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: fb 6b 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 03 e9 21 00 fb f4 7c fb 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c2 RAX: 0000000003e0bb09 RBX: 0000000000000001 RCX: ffffffff8b882c79 RDX: 0000000000000000 RSI: ffffffff8de3251e RDI: ffffffff8c158f60 RBP: ffffed1003c56488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e2b2440 R14: ffffffff90a97f50 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124816000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000030000 CR3: 0000000062c40000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148