rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12260/1:b..l rcu: (detected by 1, t=10503 jiffies, g=98629, q=130 ncpus=2) task:syz-executor state:R running task stack:21736 pid:12260 ppid:12241 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: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:ffffc90004bbf720 EFLAGS: 00000206 RAX: 82100b120b914a00 RBX: ffff888030541e00 RCX: 82100b120b914a00 RDX: ffff888030541e00 RSI: ffffffff8aaacee0 RDI: ffffffff8afc6a80 RBP: 0000000000000000 R08: ffffea0001b655b7 R09: 1ffffd400036cab6 R10: dffffc0000000000 R11: fffff9400036cab7 R12: 0000000000000002 R13: 0000000000000246 R14: ffff88805f08e8b8 R15: ffff888030542930 lock_is_held include/linux/lockdep.h:288 [inline] xa_entry include/linux/xarray.h:1216 [inline] xas_reload+0xf9/0x470 include/linux/xarray.h:1601 find_get_entry mm/filemap.c:2030 [inline] find_lock_entries+0x395/0xfe0 mm/filemap.c:2114 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 do_unlinkat+0x37b/0x570 fs/namei.c:4406 __do_sys_unlink fs/namei.c:4447 [inline] __se_sys_unlink fs/namei.c:4445 [inline] __x64_sys_unlink+0x49/0x50 fs/namei.c:4445 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: 0033:0x7fa9b718e577 RSP: 002b:00007ffe6ad79018 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa9b718e577 RDX: 00007ffe6ad79040 RSI: 00007ffe6ad790d0 RDI: 00007ffe6ad790d0 RBP: 00007ffe6ad790d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe6ad7a160 R13: 00007fa9b7211d7d R14: 00000000000add19 R15: 00007ffe6ad7a1a0 rcu: rcu_preempt kthread starved for 10536 jiffies! g98629 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:27080 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14603 Comm: syz.1.1974 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:mark_lock+0xd6/0x320 kernel/locking/lockdep.c:4656 Code: eb 24 48 c7 c0 80 f4 ea 96 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 06 02 00 00 83 3d 23 3f 83 15 00 74 36 45 31 ff 49 83 c7 60 <4c> 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 e4 33 75 00 RSP: 0018:ffffc9000c6af860 EFLAGS: 00000082 RAX: 0000000000008c90 RBX: ffff88805db55a00 RCX: ffffffff8167b524 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90da8510 RBP: 0000000000000008 R08: ffffffff90da8517 R09: 1ffffffff21b50a2 R10: dffffc0000000000 R11: fffffbfff21b50a3 R12: 0000000000000100 R13: dffffc0000000000 R14: ffff88805db564e0 R15: ffffffff907190b0 FS: 00007f053b1f66c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f81cff8 CR3: 000000006afac000 CR4: 00000000003526f0 Call Trace: mark_usage kernel/locking/lockdep.c:4599 [inline] __lock_acquire+0xd49/0x7c80 kernel/locking/lockdep.c:5091 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0xa3/0xe0 kernel/locking/spinlock.c:170 spin_lock_irq include/linux/spinlock.h:376 [inline] __set_current_blocked+0xeb/0x240 kernel/signal.c:3091 set_current_blocked kernel/signal.c:3077 [inline] signal_delivered kernel/signal.c:2938 [inline] signal_setup_done+0x189/0x310 kernel/signal.c:2950 handle_signal arch/x86/kernel/signal.c:285 [inline] arch_do_signal_or_restart+0x4a6/0x7b0 arch/x86/kernel/signal.c:312 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: 0033:0x7f053ce4d9b0 Code: 44 24 20 0f 29 44 24 30 0f 29 44 24 40 48 8b 44 24 08 ff d0 48 83 c4 50 31 c0 5b 5d 41 5c 41 5d 41 5e c3 0f 1f 80 00 00 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 c3 66 66 2e 0f 1f RSP: 002b:00007f053b1f5b38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f053d1e5fa8 RCX: 00007f053cf8efc9 RDX: 00007f053b1f5b40 RSI: 00007f053b1f5c70 RDI: 0000000000000011 RBP: 00007f053d1e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f053d1e6038 R14: 00007ffff269db10 R15: 00007ffff269dbf8