rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=2544/1/0x4000000000000000 softirq=99917/99918 fqs=8
rcu: (detected by 0, t=10506 jiffies, g=123189, q=203 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 19659 Comm: syz.2.3859 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:_find_first_zero_bit+0x6/0xb0 lib/find_bit.c:148
Code: 00 74 86 e8 9c 91 81 fd e9 7c ff ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 41 55 41 54 53 48 85 f6 74 46 48 89 f3 49 89 fe 49 bc 00 00
RSP: 0018:ffffc900064f7c38 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88802942ed90 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff88802942ed90
RBP: 0000000080000000 R08: 1ffff11005285c61 R09: 0000000000000000
R10: ffff88802942e454 R11: fffff52000c9ef78 R12: 1ffffffff1c369d3
R13: 0000000080000000 R14: 0000000000000002 R15: ffff88802942e200
FS: 00007f792f81d6c0(0000) GS:ffff888125554000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3131fff8 CR3: 0000000025928000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
find_first_zero_bit include/linux/find.h:393 [inline]
__mm_get_cid kernel/sched/sched.h:3838 [inline]
mm_get_cid kernel/sched/sched.h:3853 [inline]
sched_mm_cid_fork+0x5d5/0x1120 kernel/sched/core.c:10679
bprm_execve+0xda1/0x1460 fs/exec.c:1771
do_execveat_common+0x50d/0x690 fs/exec.c:1846
__do_sys_execveat fs/exec.c:1941 [inline]
__se_sys_execveat fs/exec.c:1934 [inline]
__x64_sys_execveat+0xc7/0xf0 fs/exec.c:1934
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f792e99c819
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:00007f792f81d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f792ec15fa0 RCX: 00007f792e99c819
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004
RBP: 00007f792ea32c91 R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f792ec16038 R14: 00007f792ec15fa0 R15: 00007f792ed3fa48
rcu: rcu_preempt kthread starved for 10465 jiffies! g123189 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:27480 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 19666 Comm: syz.0.3860 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_single+0x399/0x580 kernel/smp.c:687
Code: 33 44 89 f6 83 e6 01 31 ff e8 83 01 0c 00 41 83 e6 01 75 11 e8 38 fd 0b 00 4d 89 fe eb 3f e8 2e fd 0b 00 eb 3c 4d 89 fe f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 11 fd 0b 00
RSP: 0018:ffffc900039b6f40 EFLAGS: 00000246
RAX: ffffffff81b9c2df RBX: ffffc900039b6f88 RCX: 0000000000080000
RDX: ffffc9000f455000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900039b7020 R08: ffffffff9011dab7 R09: 1ffffffff2023b56
R10: dffffc0000000000 R11: ffffffff8173f7d0 R12: 1ffff92000736df1
R13: dffffc0000000000 R14: 1ffff92000736dec R15: 1ffff92000736dec
FS: 00007fc8bb9f66c0(0000) GS:ffff888125454000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3331fff8 CR3: 0000000077580000 CR4: 00000000003526f0
Call Trace:
loaded_vmcs_clear arch/x86/kvm/vmx/vmx.c:872 [inline]
vmx_vcpu_load_vmcs+0xcd/0x5e0 arch/x86/kvm/vmx/vmx.c:1533
vmx_vcpu_load+0x1b0/0x260 arch/x86/kvm/vmx/vmx.c:1591
kvm_arch_vcpu_load+0x25d/0xa50 arch/x86/kvm/x86.c:5182
kvm_sched_in+0x7c/0xe0 virt/kvm/kvm_main.c:6390
__fire_sched_in_preempt_notifiers kernel/sched/core.c:4847 [inline]
fire_sched_in_preempt_notifiers kernel/sched/core.c:4853 [inline]
finish_task_switch+0x85d/0x920 kernel/sched/core.c:5165
context_switch kernel/sched/core.c:5301 [inline]
__schedule+0x15e5/0x52d0 kernel/sched/core.c:6911
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238
irqentry_exit+0x599/0x620 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216
Code: 8b 3d e4 8f 55 0c 48 89 de 5b e9 13 9f 5e 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 08 00 57 11 65 8b 15 29 00 57 11 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900039b75b8 EFLAGS: 00000246
RAX: ffffffff8147df32 RBX: 0000000000000000 RCX: ffff888056145b80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900039b79b0 R08: ffff888054e453bf R09: 1ffff1100a9c8a77
R10: dffffc0000000000 R11: ffffed100a9c8a78 R12: ffff888054e45380
R13: ffff888054e45458 R14: ffff888054e453b8 R15: dffffc0000000000
kvm_check_request include/linux/kvm_host.h:2287 [inline]
vcpu_enter_guest arch/x86/kvm/x86.c:11181 [inline]
vcpu_run+0x2392/0x7b90 arch/x86/kvm/x86.c:11677
kvm_arch_vcpu_ioctl_run+0x11e6/0x20d0 arch/x86/kvm/x86.c:12025
kvm_vcpu_ioctl+0xa62/0xfd0 virt/kvm/kvm_main.c:4476
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc8bd79c819
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:00007fc8bb9f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc8bda16090 RCX: 00007fc8bd79c819
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000008
RBP: 00007fc8bd832c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc8bda16128 R14: 00007fc8bda16090 R15: 00007fc8bdb3fa48