rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=d274/1/0x4000000000000000 softirq=41229/41229 fqs=4 rcu: (detected by 1, t=10503 jiffies, g=32329, q=449 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6496 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00231-g75f5f23f8787 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:114 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:128 [inline] RIP: 0010:lock_acquire+0xda/0x360 kernel/locking/lockdep.c:5867 Code: 9c 92 83 b8 ec 0a 00 00 00 0f 85 d5 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 30 4c 89 74 24 10 4d 89 fe 4c 8b 7c 24 30 48 c7 c7 20 5d 99 8d e8 69 50 c8 09 65 ff 05 e2 fd fe 10 45 31 RSP: 0018:ffffc90000007b40 EFLAGS: 00000046 RAX: ffff8880248b5a00 RBX: 0000000000000000 RCX: 1100ae1795250400 RDX: 0000000000000000 RSI: ffffffff8b68e927 RDI: 1ffffffff338c6fc RBP: ffffffff84c7a30b R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52000000f96 R12: 0000000000000000 R13: ffffffff99c637e0 R14: 0000000000000001 R15: 0000000000000046 FS: 000055556dfed500(0000) GS:ffff888125c51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000240 CR3: 0000000068300000 CR4: 0000000000350ef0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162 debug_object_activate+0xbb/0x420 lib/debugobjects.c:818 debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_is_held_type+0x0/0x190 kernel/locking/lockdep.c:5928 Code: 9b 1d f6 90 0f 0b 90 90 90 eb b5 e8 1a fc ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 05 RSP: 0018:ffffc9000479f500 EFLAGS: 00000282 RAX: ffffffff81f7a153 RBX: ffffea0001182280 RCX: 0000000000000000 RDX: ffff8880248b5a00 RSI: 00000000ffffffff RDI: ffff8880791ea468 RBP: 0000000000000001 R08: ffffea00011822b7 R09: 1ffffd4000230456 R10: dffffc0000000000 R11: fffff94000230457 R12: ffff8880791ea468 R13: 1ffff920008f3ebc R14: ffffc9000479f5e0 R15: ffff888079786680 lock_is_held include/linux/lockdep.h:249 [inline] xa_entry include/linux/xarray.h:1226 [inline] xas_reload+0xfc/0x470 include/linux/xarray.h:1624 find_get_entry mm/filemap.c:2053 [inline] find_lock_entries+0x25b/0xa60 mm/filemap.c:2140 shmem_undo_range+0x254/0x14b0 mm/shmem.c:1107 shmem_truncate_range mm/shmem.c:1237 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365 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:473 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:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f47ce98fc57 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffdc6af6748 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f47cea10925 RCX: 00007f47ce98fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdc6af6800 RBP: 00007ffdc6af6800 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdc6af7890 R13: 00007f47cea10925 R14: 000000000003c5f6 R15: 00007ffdc6af78d0 rcu: rcu_preempt kthread starved for 10480 jiffies! g32329 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 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: CPU: 1 UID: 0 PID: 10118 Comm: syz.6.1281 Not tainted 6.16.0-rc2-syzkaller-00231-g75f5f23f8787 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 ab fc 5e f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 53 e8 27 f6 65 8b 05 3c 04 34 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc90000a08c00 EFLAGS: 00000206 RAX: f9c39ab2fc58bd00 RBX: 0000000000000216 RCX: f9c39ab2fc58bd00 RDX: 0000000000000002 RSI: ffffffff8d982505 RDI: 0000000000000001 RBP: ffffc90000a08c90 R08: ffffffff8fa10ff7 R09: 1ffffffff1f421fe R10: dffffc0000000000 R11: fffffbfff1f421ff R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff8880b8727ac0 R15: 1ffff92000141180 FS: 0000000000000000(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c71eff8 CR3: 0000000061a1d000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x408/0xc60 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d e4 27 fa 0b 48 89 de 5b e9 d3 b6 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 f0 9c 92 65 8b 15 c8 93 dc 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000477f6d8 EFLAGS: 00000202 RAX: ffffffff81b4e850 RBX: ffff8880b873b1c0 RCX: ffff888025e38000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000477f840 R08: ffffffff8fa10ff7 R09: 1ffffffff1f421fe R10: dffffc0000000000 R11: fffffbfff1f421ff R12: 1ffff110170c8385 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8641c28 csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0xf80/0x12d0 kernel/smp.c:885 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 exit_mmap+0x44c/0xb50 mm/mmap.c:1297 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f6aeed8e929 Code: Unable to access opcode bytes at 0x7f6aeed8e8ff. RSP: 002b:00007ffd8da0b5f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6aeed8e929 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffd8da0b65c R08: 000000048da0b6ef R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000000ca R13: 00000000000927c0 R14: 000000000003c728 R15: 00007ffd8da0b6b0