rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12759/1:b..l P12795/1:b..l rcu: (detected by 1, t=10502 jiffies, g=73421, q=1154 ncpus=2) task:syz.0.1350 state:R running task stack:24616 pid:12795 tgid:12759 ppid:11869 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7221 irqentry_exit+0x5e3/0x670 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x222/0x340 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 80 7e c0 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 9a 3c 04 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 7f 5c c3 09 cc 48 8d 3d 17 cf 07 RSP: 0018:ffffc9000b5cf400 EFLAGS: 00000286 RAX: 260a1c120229b400 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 000000005a44979c RSI: ffffffff8db8bd16 RDI: ffffffff8be09d60 RBP: ffffffff81ab864d R08: ffffffff81ab864d R09: ffffffff8e144f60 R10: ffffc9000b5cf518 R11: ffffffff81ad0f00 R12: 0000000000000002 R13: ffffffff8e144f60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] is_module_text_address+0x39/0x1e0 kernel/module/main.c:3856 kernel_text_address+0x94/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 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 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5894 [inline] __kvmalloc_node_noprof+0x5d5/0x920 mm/slub.c:7463 bpf_jit_binary_pack_alloc+0x105/0x2f0 kernel/bpf/core.c:1154 bpf_int_jit_compile+0x831/0x14b0 arch/x86/net/bpf_jit_comp.c:3831 bpf_prog_select_runtime+0x4a3/0x820 kernel/bpf/core.c:2546 bpf_prog_load+0x13e9/0x1a10 kernel/bpf/syscall.c:3091 __sys_bpf+0x5c3/0x8a0 kernel/bpf/syscall.c:6206 __do_sys_bpf kernel/bpf/syscall.c:6319 [inline] __se_sys_bpf kernel/bpf/syscall.c:6317 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6317 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: 0033:0x7f01eb98f749 RSP: 002b:00007f01ec81b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f01ebbe6180 RCX: 00007f01eb98f749 RDX: 0000000000000094 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f01eba13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f01ebbe6218 R14: 00007f01ebbe6180 R15: 00007ffd87d51f98 task:syz.0.1350 state:R running task stack:25336 pid:12759 tgid:12759 ppid:11869 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7078 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:392 [inline] insert_page+0x189/0x2c0 mm/memory.c:2328 kcov_mmap+0xc9/0x130 kernel/kcov.c:514 vfs_mmap include/linux/fs.h:2070 [inline] mmap_file mm/internal.h:167 [inline] __mmap_new_file_vma mm/vma.c:2462 [inline] __mmap_new_vma mm/vma.c:2525 [inline] __mmap_region mm/vma.c:2752 [inline] mmap_region+0x14f2/0x1d40 mm/vma.c:2830 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 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: 0033:0x7f01eb98f783 RSP: 002b:00007ffd87d52058 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f01ebbe6308 RCX: 00007f01eb98f783 RDX: 0000000000000003 RSI: 0000000000400000 RDI: 00007f01e97f6000 RBP: 00007f01ebbe6270 R08: 00000000000000db R09: 0000000000000000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000003 R13: 00007f01ebbe6270 R14: 0000000000000095 R15: 0000000000000003 rcu: rcu_preempt kthread starved for 10290 jiffies! g73421 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:27656 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5282 [inline] __schedule+0x14db/0x5030 kernel/sched/core.c:6894 __schedule_loop kernel/sched/core.c:6976 [inline] schedule+0x165/0x360 kernel/sched/core.c:6991 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x11b0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9b/0x2d0 kernel/rcu/tree.c:2297 kthread+0x389/0x480 kernel/kthread.c:467 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 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+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 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 e3 8f 29 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07dc0 EFLAGS: 000002c2 RAX: 0000000000c89179 RBX: ffffffff8197762e RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d9a7514 RDI: ffffffff8be09d60 RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa2daf0 R13: 1ffffffff1bd29d0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125bf7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5bf5a5e463 CR3: 0000000024698000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1be/0x4d0 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:759 start_kernel+0x386/0x3d0 init/main.c:1209 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147