rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6175/1:b..l rcu: (detected by 0, t=10503 jiffies, g=10265, q=552 ncpus=2) task:syz.0.54 state:R running task stack:25800 pid:6175 ppid:5786 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:folio_test_head include/linux/page-flags.h:798 [inline] RIP: 0010:folio_test_large include/linux/page-flags.h:819 [inline] RIP: 0010:folio_nr_pages include/linux/mm.h:2056 [inline] RIP: 0010:folio_contains+0x257/0x5c0 include/linux/pagemap.h:845 Code: 38 29 00 48 b8 00 00 00 00 00 fc ff df 41 80 7c 05 00 00 74 08 48 89 df e8 16 37 29 00 4d 29 e6 4c 8b 3b 4c 89 fe 48 83 e6 40 <31> ff e8 62 e1 d1 ff 49 83 e7 40 75 0c e8 17 dd d1 ff bb 01 00 00 RSP: 0018:ffffc9000bd77240 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffea00014d9280 RCX: ffffffff81b3b230 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea00014d9280 RBP: 1ffffd400029b251 R08: ffffea00014d9287 R09: 1ffffd400029b250 R10: dffffc0000000000 R11: fffff9400029b251 R12: 0000000000000a28 R13: 1ffffd400029b250 R14: 0000000000000000 R15: 00fff8000008022d find_lock_entries+0x660/0xfe0 mm/filemap.c:2125 shmem_undo_range+0x254/0x1a40 mm/shmem.c:1009 shmem_truncate_range mm/shmem.c:1136 [inline] shmem_evict_inode+0x273/0xa70 mm/shmem.c:1265 evict+0x486/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5e5/0x970 fs/file_table.c:392 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 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: 0033:0x7fd79338efc9 RSP: 002b:00007fd7941cf038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007fd7935e6090 RCX: 00007fd79338efc9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fd793411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd7935e6128 R14: 00007fd7935e6090 R15: 00007fff711255a8 rcu: rcu_preempt kthread starved for 10438 jiffies! g10265 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:26920 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: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:schedule_idle+0x6/0x80 kernel/sched/core.c:6791 Code: 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c f4 fe ff ff 4c 89 f7 e8 8b e8 65 f7 e9 e7 fe ff ff 66 0f 1f 44 00 00 66 0f 1f 00 41 57 <41> 56 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 1d e5 b6 8c 75 4c RSP: 0018:ffffffff8ca07d90 EFLAGS: 00000246 RAX: 75d95c8b2742ed00 RBX: ffffffff8ca93440 RCX: ffffffff8ca93440 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffffffff8ca07eb8 R08: ffffffff8e4a8b2f R09: 1ffffffff1c95165 R10: dffffc0000000000 R11: fffffbfff1c95166 R12: ffffffff8e4a8b28 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952688 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000500 CR3: 000000005a59a000 CR4: 00000000003506f0 Call Trace: do_idle+0x4ac/0x510 kernel/sched/idle.c:310 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 rest_init+0x2e2/0x300 init/main.c:744 arch_call_rest_init+0xe/0x10 init/main.c:841 start_kernel+0x459/0x4e0 init/main.c:1086 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b