rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=d324/1/0x4000000000000000 softirq=92126/92127 fqs=4
rcu: 	(detected by 0, t=10502 jiffies, g=118981, q=306 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 21313 Comm: syz.2.4095 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:80 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:699
Code: 8a e8 8e 20 13 09 48 c7 c7 00 86 13 8d 4c 89 f6 e8 df db eb 02 e9 44 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 68 01 93 7e e8 4b 36 13 09 89 c3 83 f8 08 73 60
RSP: 0018:ffffc900001f0b50 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff81680367
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8e8ae5e8
RBP: ffffc900001f0c80 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd
R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: 1ffff9200003e178
R13: ffffffff8d131da0 R14: 0000000000000001 R15: dffffc0000000000
FS:  00007f8fdceb96c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2da00e CR3: 000000002dc39000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0xc6/0x420 kernel/locking/lockdep.c:5725
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 advance_sched+0x9f3/0xc70 net/sched/sch_taprio.c:1002
 __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
 __hrtimer_run_queues+0x525/0xc10 kernel/time/hrtimer.c:1818
 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880
 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:spin_unlock include/linux/spinlock.h:391 [inline]
RIP: 0010:__text_poke+0x902/0xb40 arch/x86/kernel/alternative.c:2097
Code: 00 4d 85 ff 75 16 e8 1d 7d 56 00 eb 15 e8 16 7d 56 00 e8 01 70 53 09 4d 85 ff 74 ea e8 07 7d 56 00 fb 48 8b bc 24 e0 00 00 00 <e8> c9 1b 5d 09 e8 e4 75 53 09 89 c3 31 ff 89 c6 e8 99 80 56 00 85
RSP: 0018:ffffc900188b7a20 EFLAGS: 00000283
RAX: ffffffff81306849 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d0db000 RSI: 0000000000003ac6 RDI: ffff888017c66060
RBP: ffffc900188b7b70 R08: ffffffff911bc507 R09: 1ffffffff22378a0
R10: dffffc0000000000 R11: fffffbfff22378a1 R12: ffffffff8a8be992
R13: dffffc0000000000 R14: 1ffff92003116f54 R15: 0000000000000200
 text_poke arch/x86/kernel/alternative.c:2121 [inline]
 text_poke_bp_batch+0x4fb/0x980 arch/x86/kernel/alternative.c:2454
 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
 static_key_enable+0x1a/0x20 kernel/jump_label.c:220
 __sched_core_enable kernel/sched/core.c:398 [inline]
 sched_core_get+0xb3/0x180 kernel/sched/core.c:422
 sched_core_alloc_cookie+0x71/0xa0 kernel/sched/core_sched.c:18
 sched_core_share_pid+0x30e/0x7a0 kernel/sched/core_sched.c:185
 __do_sys_prctl kernel/sys.c:2727 [inline]
 __se_sys_prctl+0x3bb/0x1510 kernel/sys.c:2453
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8fdbf9de59
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:00007f8fdceb9028 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007f8fdc225fa0 RCX: 00007f8fdbf9de59
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e
RBP: 00007f8fdc033e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8fdc226038 R14: 00007f8fdc225fa0 R15: 00007ffe59659e48
 </TASK>
rcu: rcu_preempt kthread starved for 10494 jiffies! g118981 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:27848 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 21314 Comm: syz.2.4095 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:216
Code: e0 d2 7c 7e 65 8b 15 e1 d2 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc
RSP: 0018:ffffc9001876f398 EFLAGS: 00000246
RAX: ffffffff817bf7fd RBX: 1ffff110171e82bd RCX: ffff88802cf3bc00
RDX: 0000000000000002 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9001876f520 R08: ffffffff911bc537 R09: 1ffffffff22378a6
R10: dffffc0000000000 R11: fffffbfff22378a7 R12: ffff8880b8f415e8
R13: ffff8880b8e3d3c0 R14: dffffc0000000000 R15: 0000000000000001
FS:  00007f8fdce986c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c351d6f CR3: 000000002dc39000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:311 [inline]
 smp_call_function_many_cond+0xd9d/0x1190 kernel/smp.c:855
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:990 [inline]
 flush_tlb_mm_range+0x417/0x680 arch/x86/mm/tlb.c:1078
 tlb_flush arch/x86/include/asm/tlb.h:20 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:474 [inline]
 tlb_flush_mmu+0x1bd/0x510 mm/mmu_gather.c:300
 tlb_finish_mmu+0xf4/0x220 mm/mmu_gather.c:425
 unmap_region+0x311/0x370 mm/mmap.c:2349
 do_vmi_align_munmap+0x1057/0x16a0 mm/mmap.c:2592
 do_vmi_munmap+0x252/0x2d0 mm/mmap.c:2660
 __mmap_region mm/mmap.c:2710 [inline]
 mmap_region+0x8d9/0x2090 mm/mmap.c:2941
 do_mmap+0x98f/0x10a0 mm/mmap.c:1385
 vm_mmap_pgoff+0x1c4/0x3f0 mm/util.c:556
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8fdbf9de59
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:00007f8fdce98028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f8fdc226090 RCX: 00007f8fdbf9de59
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f8fdc033e6f R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8fdc226128 R14: 00007f8fdc226090 R15: 00007ffe59659e48
 </TASK>