rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=9914/1/0x4000000000000000 softirq=163189/163198 fqs=214 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P21381/1:b..l P21346/1:b..l rcu: (detected by 1, t=10502 jiffies, g=141793, q=151 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 21403 Comm: syz.3.3483 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:taprio_set_budgets+0x1bc/0x3b0 net/sched/sch_taprio.c:674 Code: 58 f8 41 bd ff ff ff 7f 4d 89 f7 e9 9c 00 00 00 e8 29 4d 58 f8 4c 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <4d> 89 f7 74 08 4c 89 ef e8 f7 f6 bd f8 4d 69 6d 00 e8 03 00 00 4c RSP: 0018:ffffc90000007c00 EFLAGS: 00000046 RAX: 1ffff1100bc66a81 RBX: 0000000000000004 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: 0000000004000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88805e335483 R09: 1ffff1100bc66a90 R10: dffffc0000000000 R11: ffffed100bc66a91 R12: 0000000000000001 R13: ffff88805e335408 R14: ffff88805e335400 R15: 0000000004000000 FS: 00007fb25b84d6c0(0000) GS:ffff888125d04000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555568f8a588 CR3: 0000000030696000 CR4: 00000000003526f0 Call Trace: advance_sched+0x963/0xc90 net/sched/sch_taprio.c:982 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lockdep_unregister_key+0x2c5/0x310 kernel/locking/lockdep.c:6616 Code: 65 48 8b 05 6d f1 f3 10 48 3b 44 24 10 0f 84 26 fe ff ff e8 1d b2 af 09 e8 48 b3 af 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff RSP: 0018:ffffc9000ba2f088 EFLAGS: 00000246 RAX: 4c115ecf76184800 RBX: ffff888053e44a98 RCX: 4c115ecf76184800 RDX: ffffffff93557358 RSI: ffffffff8d802285 RDI: ffffffff8bc07a60 RBP: ffff888053e44a00 R08: 0000000000000000 R09: ffffffff81aacaf8 R10: dffffc0000000000 R11: fffffbfff1f3c4ef R12: 0000000000000000 R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000a02 __qdisc_destroy+0x167/0x430 net/sched/sch_generic.c:1083 taprio_attach+0x25a/0x380 net/sched/sch_taprio.c:2160 qdisc_graft+0x1175/0x1590 net/sched/sch_api.c:1162 __tc_modify_qdisc net/sched/sch_api.c:1756 [inline] tc_modify_qdisc+0x189b/0x20e0 net/sched/sch_api.c:1812 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6963 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb25a98eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb25b84d038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb25abe6180 RCX: 00007fb25a98eec9 RDX: 0000000000048004 RSI: 00002000000007c0 RDI: 000000000000000b RBP: 00007fb25aa11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb25abe6218 R14: 00007fb25abe6180 R15: 00007fff53d00a08 task:syz.0.3469 state:R running task stack:25224 pid:21346 tgid:21345 ppid:17631 task_flags:0x40054c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:xas_reload+0x68/0x470 include/linux/xarray.h:1629 Code: 00 00 00 49 8d 5e 08 48 89 d8 48 c1 e8 03 80 3c 28 00 74 08 48 89 df e8 f6 7d 2d 00 48 8b 1b 4c 89 f8 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 90 03 00 00 45 0f b6 27 bf 40 00 00 00 44 89 e6 e8 df RSP: 0018:ffffc9000ba1f128 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: 000000000000037b RCX: ffff88802fd95ac0 RDX: 0000000000000000 RSI: ffffffff8d9d6f6f RDI: ffffc9000ba1f200 RBP: dffffc0000000000 R08: ffffea000116b437 R09: 1ffffd400022d686 R10: dffffc0000000000 R11: fffff9400022d687 R12: ffffea000116b400 R13: fffffffffffffffe R14: ffffc9000ba1f200 R15: ffff8880489d63c0 find_get_entry mm/filemap.c:2085 [inline] find_lock_entries+0x25b/0xa60 mm/filemap.c:2172 shmem_undo_range+0x254/0x14b0 mm/shmem.c:1102 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 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 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 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/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffb3118d97f RSP: 002b:00007ffb31ff9df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: 0000000003c3d000 RBX: 0000000004000000 RCX: 00007ffb3118d97f RDX: 0000000004000000 RSI: 00007ffb26e00000 RDI: 0000000000000008 RBP: 0000000000000000 R08: 0000000000000000 R09: 00000000000105c3 R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000008 R13: 00007ffb31ff9ef0 R14: 00007ffb31ff9eb0 R15: 00007ffb26e00000 task:syz.4.3476 state:R running task stack:25000 pid:21381 tgid:21379 ppid:19518 task_flags:0x400040 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137 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] do_anonymous_page mm/memory.c:5239 [inline] do_pte_missing mm/memory.c:4359 [inline] handle_pte_fault mm/memory.c:6177 [inline] __handle_mm_fault+0x3a3e/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:rep_movs_alternative+0x30/0x90 arch/x86/lib/copy_user_64.S:60 Code: 83 f9 08 73 25 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 e9 0d 35 04 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 RSP: 0018:ffffc9000c07fa18 EFLAGS: 00050206 RAX: 00007ffffffff001 RBX: 0000000000000038 RCX: 0000000000000038 RDX: 0000000000000001 RSI: 000020000028c000 RDI: ffffc9000c07faa0 RBP: ffffc9000c07fc30 R08: ffffc9000c07fad7 R09: 1ffff9200180ff5a R10: dffffc0000000000 R11: fffff5200180ff5b R12: 0000000000000002 R13: dffffc0000000000 R14: ffffc9000c07faa0 R15: 000020000028c000 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline] _inline_copy_from_user include/linux/uaccess.h:178 [inline] _copy_from_user+0x7a/0xb0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] copy_msghdr_from_user net/socket.c:2560 [inline] recvmsg_copy_msghdr net/socket.c:2816 [inline] ___sys_recvmsg+0x12e/0x510 net/socket.c:2888 do_recvmmsg+0x307/0x770 net/socket.c:2987 __sys_recvmmsg net/socket.c:3061 [inline] __do_sys_recvmmsg net/socket.c:3084 [inline] __se_sys_recvmmsg net/socket.c:3077 [inline] __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3077 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f077c58eec9 RSP: 002b:00007f077d4da038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f077c7e6090 RCX: 00007f077c58eec9 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f077c611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f077c7e6128 R14: 00007f077c7e6090 R15: 00007ffce3c9c448 rcu: rcu_preempt kthread starved for 10074 jiffies! g141793 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:26936 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 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+0x4bc/0x870 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc 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 53 b1 1a 00 f3 0f 1e fa fb f4 c8 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: 08c46cc819890e00 RBX: ffffffff8196d367 RCX: 08c46cc819890e00 RDX: 0000000000000001 RSI: ffffffff8d7edf31 RDI: ffffffff8bc07a60 RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9e2770 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a54b58 FS: 0000000000000000(0000) GS:ffff888125e04000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f54261a2835 CR3: 00000000324f6000 CR4: 00000000003526f0 DR0: 0000000000000004 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x1e7/0x510 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