rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=67b/1/0x4000000000000000 softirq=9563/9563 fqs=0 (detected by 0, t=10502 jiffies, g=12217, q=307) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5063 Comm: syz.0.17 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:lock_acquire+0x209/0x3f0 kernel/locking/lockdep.c:5627 Code: 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b 00 <65> 48 8b 04 25 28 00 00 00 48 3b 84 24 c0 00 00 00 0f 85 f9 00 00 RSP: 0018:ffffc90000dd0b40 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ba22413c14f92c00 RDX: 0000000000000000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340 RBP: ffffc90000dd0c60 R08: dffffc0000000000 R09: fffffbfff1ff6e19 R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: ffffffff8c11c360 R13: 1ffff920001ba174 R14: 0000000000000046 R15: dffffc0000000000 FS: 00007f373f8a26c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000300 CR3: 000000002a4c0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] advance_sched+0x6ca/0x940 net/sched/sch_taprio.c:769 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194 Code: 74 05 e8 2e 47 cc f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f6 d4 9f f7 65 8b 05 97 d4 50 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000302ee00 EFLAGS: 00000206 RAX: ba22413c14f92c00 RBX: 0000000000000a06 RCX: ba22413c14f92c00 RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001 RBP: ffffc9000302ee90 R08: dffffc0000000000 R09: fffffbfff1ff6e32 R10: fffffbfff1ff6e32 R11: 1ffffffff1ff6e31 R12: dffffc0000000000 R13: 0000001bfcbd69fc R14: ffff888072402ae8 R15: 1ffff92000605dc0 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] taprio_change+0x3ff2/0x4ed0 net/sched/sch_taprio.c:1620 qdisc_create+0x7bd/0x1170 net/sched/sch_api.c:1265 tc_modify_qdisc+0xaa1/0x1770 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg+0x190/0x250 net/socket.c:2526 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3740632b69 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:00007f373f8a2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3740859fa0 RCX: 00007f3740632b69 RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004 RBP: 00007f37406b5df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3740859fa0 R15: 00007ffd4f31d4f8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g12217 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=6817 rcu: rcu_preempt kthread starved for 10502 jiffies! g12217 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28032 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5063 Comm: syz.0.17 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_preemption_disabled+0x18/0x110 lib/smp_processor_id.c:14 Code: 00 cc 48 c7 c7 e0 92 59 8a 48 c7 c6 20 93 59 8a eb 00 55 41 57 41 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 <65> 8b 05 a9 d7 59 76 65 8b 0d 12 32 5a 76 f7 c1 ff ff ff 7f 74 1f RSP: 0018:ffffc90000dd0c00 EFLAGS: 00000086 RAX: ba22413c14f92c00 RBX: ffff88807e165940 RCX: 0000000000000001 RDX: 0000000000010000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340 RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520001ba180 R11: 1ffff920001ba180 R12: 0000000000000002 R13: 0000000000000046 R14: ffff888072402b00 R15: ffff88807e166480 FS: 00007f373f8a26c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000300 CR3: 000000002a4c0000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline] lock_is_held_type+0x100/0x190 kernel/locking/lockdep.c:5667 lock_is_held include/linux/lockdep.h:287 [inline] advance_sched+0xd6/0x940 net/sched/sch_taprio.c:719 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194 Code: 74 05 e8 2e 47 cc f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 f6 d4 9f f7 65 8b 05 97 d4 50 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc9000302ee00 EFLAGS: 00000206 RAX: ba22413c14f92c00 RBX: 0000000000000a06 RCX: ba22413c14f92c00 RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001 RBP: ffffc9000302ee90 R08: dffffc0000000000 R09: fffffbfff1ff6e32 R10: fffffbfff1ff6e32 R11: 1ffffffff1ff6e31 R12: dffffc0000000000 R13: 0000001bfcbd69fc R14: ffff888072402ae8 R15: 1ffff92000605dc0 spin_unlock_irqrestore include/linux/spinlock.h:418 [inline] taprio_change+0x3ff2/0x4ed0 net/sched/sch_taprio.c:1620 qdisc_create+0x7bd/0x1170 net/sched/sch_api.c:1265 tc_modify_qdisc+0xaa1/0x1770 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2436 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg+0x190/0x250 net/socket.c:2526 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3740632b69 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:00007f373f8a2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3740859fa0 RCX: 00007f3740632b69 RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004 RBP: 00007f37406b5df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3740859fa0 R15: 00007ffd4f31d4f8