rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=84ec/1/0x4000000000000000 softirq=265004/265007 fqs=0 rcu: (detected by 0, t=10506 jiffies, g=244957, q=183 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3822 Comm: syz.6.5745 Not tainted 6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0x1265/0x2100 kernel/locking/lockdep.c:5224 Code: e0 a5 2a 8c e8 3c b2 e4 ff 48 bf 00 00 00 00 00 fc ff df 90 0f 0b 90 90 90 31 db 48 83 c3 40 48 89 d8 48 c1 e8 03 80 3c 38 00 <74> 12 48 89 df e8 b1 2e 8c 00 48 bf 00 00 00 00 00 fc ff df 48 83 RSP: 0018:ffffc90000a18930 EFLAGS: 00000046 RAX: 1ffffffff27d8dd8 RBX: ffffffff93ec6ec0 RCX: ffffffff819cc675 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: 97064f26aa3bd169 R08: ffffffff9454984f R09: 1ffffffff28a9309 R10: dffffc0000000000 R11: fffffbfff28a930a R12: ffff88802cb83c00 R13: ffff88802cb83c00 R14: 1ffff110059708f1 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0063) knlGS:00000000f50c6b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 000000000c32a01d CR3: 0000000056670000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 debug_object_deactivate+0x158/0x390 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:460 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:502 __run_hrtimer kernel/time/hrtimer.c:1769 [inline] __hrtimer_run_queues+0x305/0xd30 kernel/time/hrtimer.c:1865 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1927 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 5e e3 1d f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 e3 4c 84 f5 65 8b 05 84 c1 f8 73 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc900106bedc0 EFLAGS: 00000206 RAX: 7a87431c2a8d8f00 RBX: 1ffff920020d7dbc RCX: ffffffff819d29ca RDX: dffffc0000000000 RSI: ffffffff8c2aa440 RDI: 0000000000000001 RBP: ffffc900106bee50 R08: ffffffff94549937 R09: 1ffffffff28a9326 R10: dffffc0000000000 R11: fffffbfff28a9327 R12: dffffc0000000000 R13: 1ffff920020d7db8 R14: ffffc900106bede0 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] taprio_change+0x351b/0x44f0 net/sched/sch_taprio.c:1973 taprio_init+0x9da/0xc80 net/sched/sch_taprio.c:2114 qdisc_create+0x9d4/0x11a0 net/sched/sch_api.c:1360 tc_modify_qdisc+0xbbb/0x1f10 rtnetlink_rcv_msg+0x73f/0xcf0 net/core/rtnetlink.c:6921 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 ____sys_sendmsg+0x53a/0x860 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2659 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fa7579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f50c655c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000800007c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10506 jiffies! g244957 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:25784 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 2901 Comm: syz-executor Not tainted 6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bb2/0x2d30 kernel/smp.c:885 Code: 01 31 ff e8 30 f5 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 e0 f0 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df 0f b6 04 03 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 bb f0 0b 00 eb db 44 RSP: 0018:ffffc900048ef4e0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170e88f9 RCX: ffff888035c73c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900048ef6e0 R08: ffffffff81b5cd10 R09: 1ffffffff28a930e R10: dffffc0000000000 R11: fffffbfff28a930f R12: ffff8880b863fb48 R13: ffff8880b87447c8 R14: ffff8880b863fb40 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b8600000(0063) knlGS:0000000057757440 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f5075510 CR3: 0000000076458000 CR4: 00000000003526f0 Call Trace: 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:966 [inline] flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054 dup_mmap kernel/fork.c:787 [inline] dup_mm kernel/fork.c:1700 [inline] copy_mm+0x18af/0x2160 kernel/fork.c:1752 copy_process+0x17d1/0x3cf0 kernel/fork.c:2403 kernel_clone+0x226/0x8e0 kernel/fork.c:2815 __do_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:254 [inline] __se_compat_sys_ia32_clone arch/x86/kernel/sys_ia32.c:240 [inline] __ia32_compat_sys_ia32_clone+0x265/0x2e0 arch/x86/kernel/sys_ia32.c:240 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:386 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fbf579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f75afcbc EFLAGS: 00000206 ORIG_RAX: 0000000000000078 RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000577574a8 RBP: 00000000f744cff4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000