rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5950/1:b..l P6055/1:b..l P4533/1:b..l rcu: (detected by 1, t=10502 jiffies, g=7525, q=1541 ncpus=2) task:kworker/u8:9 state:R running task stack:23768 pid:4533 tgid:4533 ppid:2 task_flags:0x24248060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 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:page_ext_next include/linux/page_ext.h:108 [inline] RIP: 0010:page_ext_iter_next include/linux/page_ext.h:156 [inline] RIP: 0010:__page_table_check_zero+0x2f3/0x5d0 mm/page_table_check.c:139 Code: c6 48 89 04 24 e8 2d e1 8e ff 48 8b 04 24 48 85 c0 0f 84 9c 00 00 00 e8 ab e5 8e ff 48 8b 44 24 18 80 38 00 0f 85 96 02 00 00 <4c> 03 25 46 6a b5 18 48 83 c5 01 e8 8d e5 8e ff 4d 85 e4 0f 85 ca RSP: 0018:ffffc9000ea16f98 EFLAGS: 00000246 RAX: fffffbfff35c4da8 RBX: 0000000000056e77 RCX: ffffffff822d02d3 RDX: ffff88803579a440 RSI: ffffffff822d02e5 RDI: 0000000000000007 RBP: 0000000000000006 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000006e77 R11: 0000000000000001 R12: ffff88801e6284e0 R13: ffff88801e62852c R14: 0000000000000003 R15: dffffc0000000000 page_table_check_free include/linux/page_table_check.h:43 [inline] free_pages_prepare mm/page_alloc.c:1249 [inline] __free_frozen_pages+0x7df/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 new_handle fs/jbd2/transaction.c:457 [inline] jbd2__journal_start+0x249/0x6a0 fs/jbd2/transaction.c:490 __ext4_journal_start_sb+0x195/0x690 fs/ext4/ext4_jbd2.c:115 __ext4_journal_start fs/ext4/ext4_jbd2.h:242 [inline] ext4_do_writepages+0xc5f/0x3490 fs/ext4/inode.c:2846 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:2953 do_writepages+0x277/0x600 mm/page-writeback.c:2636 __writeback_single_inode+0x160/0xfb0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x601/0xf90 fs/fs-writeback.c:1976 wb_writeback+0x419/0xb70 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x14d/0xbe0 fs/fs-writeback.c:2343 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 task:fido_id state:R running task stack:23384 pid:6055 tgid:6055 ppid:5834 task_flags:0x400000 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 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:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x201/0x2f0 kernel/locking/lockdep.c:5882 Code: 8b 78 08 4c 89 e2 48 89 de e8 1b dc fe ff 65 ff 0d 04 7b 37 12 0f 85 39 fe ff ff e8 29 e0 93 ff e9 2f fe ff ff e8 7f e4 08 00 <84> c0 0f 85 42 fe ff ff 80 3d 73 0b f9 0e 00 0f 85 35 fe ff ff c6 RSP: 0018:ffffc9000518ee48 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffffffff8e5c4e00 RCX: ffffc90005190001 RDX: 0000000000000000 RSI: ffffffff8c157460 RDI: ffffffff8df3eda8 RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000a7d34 R12: ffffffff816adac4 R13: ffffc9000518ef00 R14: ffffc9000518f3a0 R15: ffffc9000518ef34 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x3f9/0x20a0 arch/x86/kernel/unwind_orc.c:479 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_noprof+0x1cb/0x3b0 mm/slub.c:4204 mt_alloc_one lib/maple_tree.c:176 [inline] mas_alloc_nodes+0x18b/0x8b0 lib/maple_tree.c:1249 mas_node_count_gfp+0x105/0x130 lib/maple_tree.c:1331 mas_preallocate+0x7e0/0xde0 lib/maple_tree.c:5534 vma_iter_prealloc mm/vma.h:463 [inline] __mmap_new_vma mm/vma.c:2461 [inline] __mmap_region+0x1104/0x25e0 mm/vma.c:2622 mmap_region+0x1ab/0x3f0 mm/vma.c:2692 do_mmap+0xa3e/0x1210 mm/mmap.c:561 vm_mmap_pgoff+0x281/0x450 mm/util.c:579 vm_mmap+0x8e/0xc0 mm/util.c:615 elf_map fs/binfmt_elf.c:384 [inline] elf_load+0x36d/0x780 fs/binfmt_elf.c:407 load_elf_binary+0x13c8/0x4f00 fs/binfmt_elf.c:1173 search_binary_handler fs/exec.c:1670 [inline] exec_binprm fs/exec.c:1702 [inline] bprm_execve fs/exec.c:1754 [inline] bprm_execve+0x8c3/0x1650 fs/exec.c:1730 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1860 do_execve fs/exec.c:1934 [inline] __do_sys_execve fs/exec.c:2010 [inline] __se_sys_execve fs/exec.c:2005 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2005 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: 0033:0x7fd620c1a107 RSP: 002b:00007fff2103f318 EFLAGS: 00000206 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055891fff4140 RCX: 00007fd620c1a107 RDX: 0000558957b76f40 RSI: 00007fff2103f430 RDI: 00007fff2103fc30 RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000206 R12: 0000558957b76f40 R13: 00007fff2103f430 R14: 000000000000000d R15: 0000000000000009 task:kworker/0:7 state:R running task stack:25240 pid:5950 tgid:5950 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: events_power_efficient gc_worker Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109 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:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5875 Code: 76 37 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 12 b8 10 0f 0f 82 74 02 00 00 8b 35 fa e9 10 0f 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 a9 75 37 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc9000439fae0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e5c4e00 RCX: 00000000450c12e1 RDX: 0000000000000000 RSI: ffffffff8de0b1d5 RDI: ffffffff8c1574e0 RBP: 0000000000000002 R08: 2c4b88301fba7ebf R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] gc_worker+0x241/0x16e0 net/netfilter/nf_conntrack_core.c:1549 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3321 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 9859 jiffies! g7525 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:27784 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6879 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+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 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-rc7-syzkaller-00120-g5f33ebd2018c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 6b 6d 02 e9 83 fb 02 00 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 43 79 23 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 000000000180dc69 RBX: 0000000000000001 RCX: ffffffff8b869c99 RDX: 0000000000000000 RSI: ffffffff8de30472 RDI: ffffffff8c1574e0 RBP: ffffed1003c56488 R08: 0000000000000001 R09: ffffed10170a6645 R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801e2b2440 R14: ffffffff90a94250 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124820000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558c1405c8 CR3: 0000000060c1a000 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