rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9135/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=32537, q=169 ncpus=2)
task:syz.4.724 state:R running task stack:26664 pid:9135 tgid:9135 ppid:5816 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:55 [inline]
RIP: 0010:stack_access_ok+0x0/0x200 arch/x86/kernel/unwind_orc.c:409
Code: 20 ff ff ff 44 8b 85 30 ff ff ff e9 ba fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> b8 00 00 00 00 00 fc ff df 41 57 41 56 4c 8d 77 08 41 55 41 54
RSP: 0018:ffffc900048df878 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff9120f558
RDX: 0000000000000008 RSI: ffffc900048df938 RDI: ffffc900048df940
RBP: ffffc900048df988 R08: ffffffff9120f55c R09: 00000000ffffffff
R10: 0000000000000002 R11: 0000000000006cdb R12: ffffc900048df990
R13: ffffc900048df940 R14: ffffc900048df940 R15: ffffc900048df974
deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
unwind_next_frame+0xb7d/0x20b0 arch/x86/kernel/unwind_orc.c:600
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:773
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/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]
kfree+0x2f8/0x6e0 mm/slub.c:6878
__free_fdtable fs/file.c:107 [inline]
put_files_struct.part.0+0x261/0x330 fs/file.c:513
put_files_struct fs/file.c:528 [inline]
exit_files+0xb7/0xe0 fs/file.c:526
do_exit+0x1772/0x2bd0 kernel/exit.c:966
do_group_exit+0xd3/0x2a0 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+0x3e/0x50 kernel/exit.c:1121
x64_sys_call+0x151c/0x1740 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1be478f749
RSP: 002b:00007ffc611e3798 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1be478f749
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc611e37fc R08: 0000000e611e388f R09: 00000000000927c0
R10: 000000000000d174 R11: 0000000000000246 R12: 000000000000008b
R13: 00000000000927c0 R14: 0000000000070ee8 R15: 00007ffc611e3850
rcu: rcu_preempt kthread starved for 10463 jiffies! g32537 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:27880 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: b6 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 39 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6
RAX: 0000000000bdd185 RBX: 0000000000000001 RCX: ffffffff8b7826d9
RDX: 0000000000000000 RSI: ffffffff8dace031 RDI: ffffffff8bf2b380
RBP: ffffed1003b58498 R08: 0000000000000001 R09: ffffed10170a673d
R10: ffff8880b85339eb R11: ffff88801dac2ff0 R12: 0000000000000001
R13: ffff88801dac24c0 R14: ffffffff9088b8d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3c991eef98 CR3: 000000005c597000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148