syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 GPs behind) idle=e2dc/0/0x1 softirq=11427/11428 fqs=2099
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:        0          0            0
rcu: 	cputime:        0          0            0   ==> 52500(ms)
rcu: 	(detected by 1, t=10502 jiffies, g=9613, q=593 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:-1 [inline]
RIP: 0010:__lock_acquire+0xe60/0x7c80 kernel/locking/lockdep.c:5121
Code: 00 74 12 4c 89 f7 e8 bf f2 75 00 49 b8 00 00 00 00 00 fc ff df 4d 89 3e 48 8b 44 24 78 42 0f b6 04 00 84 c0 0f 85 60 5c 00 00 <48> 8b 44 24 40 8b 18 48 85 db 4c 8b b4 24 a8 00 00 00 74 5a 83 fb
RSP: 0018:ffffc900000078c0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8ca93f10 RCX: ffffffff96e9b401
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90d94500
RBP: ffffc90000007b08 R08: dffffc0000000000 R09: 1ffffffff21b28a0
R10: dffffc0000000000 R11: fffffbfff21b28a1 R12: 0000000000000000
R13: ffffffff8ca93440 R14: ffffffff8ca93f20 R15: ffffffffffffffff
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003c80 CR3: 0000000076e53000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 advance_sched+0xa15/0xc80 net/sched/sch_taprio.c:1001
 __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
 __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148
Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 23 bb 40 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56
RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c2
RAX: 85f03efeb397af00 RBX: ffffffff8161881b RCX: 85f03efeb397af00
RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffffffff8ca07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65
R10: dffffc0000000000 R11: ffffed10171c6d66 R12: ffffffff8e4a2128
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952688
 arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:753
 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
 cpuidle_idle_call kernel/sched/idle.c:170 [inline]
 do_idle+0x1eb/0x510 kernel/sched/idle.c:282
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380
 rest_init+0x2e2/0x300 init/main.c:744
 arch_call_rest_init+0xe/0x10 init/main.c:841
 start_kernel+0x459/0x4e0 init/main.c:1086
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
 secondary_startup_64_no_verify+0x179/0x17b
 </TASK>