rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=157c/1/0x4000000000000000 softirq=17207/17210 fqs=0
rcu: (detected by 1, t=10502 jiffies, g=12877, q=819 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5839 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:task_wait_context kernel/locking/lockdep.c:4786 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4875 [inline]
RIP: 0010:__lock_acquire+0x99a/0x2cf0 kernel/locking/lockdep.c:5187
Code: 91 8d e8 c9 ac 89 ff 4c 89 f7 e8 21 88 89 ff 48 c7 c7 54 4e 83 8d e8 b5 ac 89 ff e8 d0 d0 94 ff e8 4b 9b 03 00 e9 93 0a 00 00 <41> 83 be 18 0b 00 00 00 41 0f 94 c4 41 80 f4 03 41 3b 9e 28 0b 00
RSP: 0018:ffffc90000007a78 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 0000000000000002 RCX: 00000000000e497e
RDX: 0000000000000003 RSI: 0000000000004000 RDI: 0000000000000000
RBP: ffff88802b19aa00 R08: ffffffff89707644 R09: ffff88801112f2c0
R10: dffffc0000000000 R11: ffffffff89707580 R12: 0000000000000003
R13: ffff88802b19aa00 R14: ffff88802b199e80 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888125e1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a4a8ade80 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
spin_lock include/linux/spinlock.h:351 [inline]
advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:930
__run_hrtimer kernel/time/hrtimer.c:1777 [inline]
__hrtimer_run_queues+0x51c/0xc30 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:101 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x4e1/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: bd 00 00 00 00 00 fc ff df 4c 8b 64 24 20 4c 8b 6c 24 48 0f 84 79 15 00 00 e9 03 02 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 <48> 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45
RSP: 0018:ffffc90003eef3d8 EFLAGS: 00000202
RAX: 0000000000000010 RBX: ffffffff8f99459c RCX: 0000000080000000
RDX: ffffffff8f99458c RSI: ffffffff9014d97c RDI: ffffffff8bc08300
RBP: ffffffff8f99458c R08: 0000000000000005 R09: ffffffff8df41aa0
R10: ffffc90003eef558 R11: fffff520007ddead R12: ffffffff816a9d83
R13: ffffffff8f99458c R14: ffffc90003eef508 R15: 0000000000006a9d
__unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6670 [inline]
kmem_cache_free+0x197/0x620 mm/slub.c:6781
anon_vma_chain_free mm/rmap.c:146 [inline]
unlink_anon_vmas+0x614/0x670 mm/rmap.c:446
free_pgtables+0x735/0x9d0 mm/memory.c:414
exit_mmap+0x431/0xb10 mm/mmap.c:1288
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x169/0x230 kernel/exit.c:581
do_exit+0x627/0x22f0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
__do_sys_exit_group kernel/exit.c:1123 [inline]
__se_sys_exit_group kernel/exit.c:1121 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121
x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a4a0f16c5
Code: Unable to access opcode bytes at 0x7f6a4a0f169b.
RSP: 002b:00007ffc568f36d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000055772fdadf60 RCX: 00007f6a4a0f16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000055772fd8d910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc568f3720 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10502 jiffies! g12877 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:27480 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 5945 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xcc5/0x1260 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 e4 97 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 8f 93 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 73 93
RSP: 0018:ffffc900035274a0 EFLAGS: 00000293
RAX: ffffffff81b5644d RBX: 1ffff110170c856d RCX: ffff88802621db80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900035275e0 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff1b17e7da0 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x60a/0x1170 arch/x86/mm/tlb.c:1472
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x174/0xb10 mm/mmap.c:1263
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x169/0x230 kernel/exit.c:581
do_exit+0x627/0x22f0 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f13f25c2005
Code: Unable to access opcode bytes at 0x7f13f25c1fdb.
RSP: 002b:00007ffe7a79b460 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f13f25c2005
RDX: 00007ffe7a79b4a0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe7a79b50c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000063 R14: 000000000001a85f R15: 00007ffe7a79b560