rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=488c/1/0x4000000000000000 softirq=93000/93001 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16871/1:b..l rcu: (detected by 1, t=10506 jiffies, g=92469, q=388 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 16865 Comm: syz.0.2798 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:separate_irq_context kernel/locking/lockdep.c:191 [inline] RIP: 0010:__lock_acquire+0xd65/0x1a40 kernel/locking/lockdep.c:5221 Code: 10 49 8b 7e 10 2e 2e 2e ff d0 85 c0 0f 88 29 ff ff ff 4d 85 ed 0f 84 f2 04 00 00 e8 f5 9f ff ff e9 c7 f8 ff ff be fe ff ff ff ff ff ff ff bf ff ff ff ff c7 44 24 48 01 00 00 00 41 b8 ff ff RSP: 0018:ffffc90000007ca8 EFLAGS: 00000002 RAX: 0000000000000048 RBX: ffff88804e00b108 RCX: 0000000000000200 RDX: 0000000000000000 RSI: 00000000fffffffe RDI: ffff88804e00b0e0 RBP: ffff88804e00a540 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000007 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 FS: 00007f8b1899b6c0(0000) GS:ffff8881240e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c429c57 CR3: 000000005939b000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] advance_sched+0x718/0xd20 net/sched/sch_taprio.c:992 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 bb ef 4e 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 06 a2 16 0f 0f 82 ac 02 00 00 8b 35 ce d5 16 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d ef 4e 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc900044379e0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: ba444cca68f401c0 RDX: 0000000000000000 RSI: ffffffff8e137c0e RDI: ffffffff8c3e9b80 RBP: ffff888075a564e0 R08: 00000000ffffffff R09: 000000000000089d R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 futex_wait_setup+0xeb/0x540 kernel/futex/waitwake.c:657 __futex_wait+0x19f/0x300 kernel/futex/waitwake.c:717 futex_wait+0xe6/0x370 kernel/futex/waitwake.c:750 do_futex+0x265/0x440 kernel/futex/syscalls.c:133 __do_sys_futex kernel/futex/syscalls.c:210 [inline] __se_sys_futex kernel/futex/syscalls.c:191 [inline] __x64_sys_futex+0x34f/0x4d0 kernel/futex/syscalls.c:191 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b17b9ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8b1899b0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f8b17e15fa8 RCX: 00007f8b17b9ce59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8b17e15fa8 RBP: 00007f8b17e15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8b17e16038 R14: 00007ffdfad9b7c0 R15: 00007ffdfad9b8a8 task:syz.5.2800 state:R running task stack:27560 pid:16871 tgid:16869 ppid:14276 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665 RIP: 0010:timestamp_truncate fs/inode.c:2856 [inline] RIP: 0010:current_time+0x1e2/0x3b0 fs/inode.c:2451 Code: 23 01 00 00 e8 0f da 72 ff 48 8b 44 24 08 48 ba 00 00 00 00 00 fc ff df 48 8d b8 78 06 00 00 48 89 f9 48 c1 e9 03 80 3c 11 00 <0f> 85 8f 01 00 00 48 8b 80 78 06 00 00 4c 89 ff 4c 39 e8 48 89 c6 RSP: 0018:ffffc90003567780 EFLAGS: 00000246 RAX: ffff888027224000 RBX: 000000002bad92fb RCX: 1ffff11004e448cf RDX: dffffc0000000000 RSI: ffffffff8296a611 RDI: ffff888027224678 RBP: ffffc90003567818 R08: 0000000000000006 R09: 7fffffffffffffff R10: 000000006a41b211 R11: 0000000000000000 R12: 0000000000000001 R13: 000000006a41b211 R14: 1ffff920006acef2 R15: 7fffffffffffffff atime_needs_update+0x33f/0x6b0 fs/inode.c:2295 pick_link+0x3b0/0x13c0 fs/namei.c:2044 step_into_slowpath+0x9ba/0xf90 fs/namei.c:2127 step_into fs/namei.c:2152 [inline] walk_component fs/namei.c:2288 [inline] link_path_walk+0xf28/0x1cc0 fs/namei.c:2656 path_openat+0x1c9/0x4280 fs/namei.c:4855 do_file_open+0x20e/0x430 fs/namei.c:4888 do_sys_openat2+0x10f/0x1e0 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb32ff5d68e RSP: 002b:00007fb330e39ec8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fb330e3a6c0 RCX: 00007fb32ff5d68e RDX: 0000000000000000 RSI: 00007fb330e39f90 RDI: ffffffffffffff9c RBP: 00007fb330032e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb330216038 R14: 00007fb330215fa0 R15: 00007fff5dee9a08 rcu: rcu_preempt kthread starved for 10506 jiffies! g92469 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:27592 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 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: 15001 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline] RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline] RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x582/0x16c0 kernel/smp.c:892 Code: 00 45 85 e4 74 54 48 b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 b9 95 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 2c RSP: 0018:ffffc9000378f618 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fcea8d RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888077cb2540 RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880 FS: 00005555786bd500(0000) GS:ffff8881241e0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efe925456b8 CR3: 0000000073aab000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x45f/0x16f0 arch/x86/mm/tlb.c:1451 dup_mmap+0x1307/0x21b0 mm/mmap.c:1905 dup_mm kernel/fork.c:1538 [inline] copy_mm kernel/fork.c:1590 [inline] copy_process+0x4588/0x8030 kernel/fork.c:2288 kernel_clone+0x176/0x9d0 kernel/fork.c:2747 __do_sys_clone+0xd9/0x120 kernel/fork.c:2888 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efe917c58d2 Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffcf3ac8e70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffcf3ac8e70 RCX: 00007efe917c58d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffcf3ac8ffc R08: 0000000000000000 R09: 0000000000000001 R10: 00005555786bd7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000004 R14: 00000000000e6736 R15: 00007ffcf3ac9050