rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6184/1:b..l P7233/1:b..l P7207/1:b..l rcu: (detected by 0, t=10502 jiffies, g=18653, q=229 ncpus=2) task:syz.0.309 state:R running task stack:26888 pid:7207 tgid:7207 ppid:5870 task_flags:0x40044c flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1756 [inline] zap_pmd_range mm/memory.c:1818 [inline] zap_pud_range mm/memory.c:1847 [inline] zap_p4d_range mm/memory.c:1868 [inline] unmap_page_range+0x3a79/0x4370 mm/memory.c:1889 unmap_single_vma mm/memory.c:1932 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1976 exit_mmap+0x248/0xb50 mm/mmap.c:1280 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa8b818ebe9 RSP: 002b:00007ffceeb701a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffdfc RBX: 000000000003682d RCX: 00007fa8b818ebe9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa8b83b5fac RBP: 0000000000000fd2 R08: 7fffffffffffffff R09: 00000008eeb7049f R10: 00007ffceeb702a0 R11: 0000000000000246 R12: 00007fa8b83b5fac R13: 00007ffceeb702a0 R14: 00000000000377ff R15: 00007ffceeb702c0 task:syz.5.315 state:R running task stack:24160 pid:7233 tgid:7226 ppid:5868 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline] RIP: 0010:__rcu_read_unlock+0x20/0xe0 kernel/rcu/tree_plugin.h:435 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3c 25 08 50 a0 92 <48> 8d 9f 44 04 00 00 49 89 dc 49 c1 ec 03 43 0f b6 04 3c 84 c0 75 RSP: 0018:ffffc9001d80f248 EFLAGS: 00000282 RAX: 82f6e5d93de52600 RBX: ffffffff90334c01 RCX: 82f6e5d93de52600 RDX: 0000000000000001 RSI: ffffffff8dba6cac RDI: ffff88802bf45a00 RBP: dffffc0000000000 R08: ffffc9001d80f398 R09: ffffc9001d80f3f8 R10: dffffc0000000000 R11: fffff52003b01e81 R12: ffffc9001d80f3a8 R13: ffffc9001d808000 R14: ffffc9001d80f3a8 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:873 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19ae/0x2390 arch/x86/kernel/unwind_orc.c:680 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4180 [inline] slab_alloc_node mm/slub.c:4229 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4236 lsm_inode_alloc security/security.c:755 [inline] security_inode_alloc+0x39/0x330 security/security.c:1697 inode_init_always_gfp+0x9ed/0xdc0 fs/inode.c:306 inode_init_always include/linux/fs.h:3308 [inline] alloc_inode+0x82/0x1b0 fs/inode.c:353 iget5_locked+0x4a/0xa0 fs/inode.c:1355 nilfs_iget_locked+0xae/0xf0 fs/nilfs2/inode.c:552 nilfs_dat_read+0xbe/0x330 fs/nilfs2/dat.c:506 nilfs_load_super_root fs/nilfs2/the_nilfs.c:118 [inline] load_nilfs+0x4e4/0xf90 fs/nilfs2/the_nilfs.c:308 nilfs_fill_super+0x2a8/0x650 fs/nilfs2/super.c:1075 nilfs_get_tree+0x4f4/0x870 fs/nilfs2/super.c:1228 vfs_get_tree+0x92/0x2b0 fs/super.c:1815 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4324 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f888d79038a RSP: 002b:00007f888e576e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f888e576ef0 RCX: 00007f888d79038a RDX: 0000200000000180 RSI: 0000200000000040 RDI: 00007f888e576eb0 RBP: 0000200000000180 R08: 00007f888e576ef0 R09: 00000000002000c6 R10: 00000000002000c6 R11: 0000000000000246 R12: 0000200000000040 R13: 00007f888e576eb0 R14: 0000000000000ac5 R15: 0000200000001340 task:udevd state:R running task stack:22760 pid:6184 tgid:6184 ppid:5227 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 cb e1 02 11 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900050770f0 EFLAGS: 00000206 RAX: 057304a5e23fa800 RBX: 0000000000000202 RCX: 057304a5e23fa800 RDX: 0000000000000000 RSI: ffffffff8dba6cac RDI: ffffffff8be33680 RBP: ffff8880244228f0 R08: ffffc900050774d0 R09: ffffc90005077278 R10: dffffc0000000000 R11: fffff52000a0ee51 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e139ee0 R15: ffff888024421e00 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+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] free_unref_folios+0xdbd/0x1520 mm/page_alloc.c:2952 folios_put_refs+0x559/0x640 mm/swap.c:997 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1157 shmem_truncate_range mm/shmem.c:1269 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1397 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fad254a7407 RSP: 002b:00007ffde8b63350 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007fad25be8880 RCX: 00007fad254a7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007fad25be86e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 000055f16cb8d190 R14: 0000000000000008 R15: 000055f16cbb2540 rcu: rcu_preempt kthread starved for 10578 jiffies! g18653 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:27360 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 3e 9d 96 f5 cc cc cc 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 f3 86 0e 00 f3 0f 1e fa fb f4 13 9d 96 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c2 RAX: 1b897b1e44296400 RBX: ffffffff819683c8 RCX: 1b897b1e44296400 RDX: 0000000000000001 RSI: ffffffff8d9b77e3 RDI: ffffffff8be33680 RBP: ffffc90000197f20 R08: ffff8880b8732f9b R09: 1ffff110170e65f3 R10: dffffc0000000000 R11: ffffed10170e65f4 R12: ffffffff8fa38a30 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100395eb40 FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fad25bdc000 CR3: 000000007f75c000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:757 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:330 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x147