rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12212/1:b..l rcu: (detected by 1, t=10502 jiffies, g=50073, q=367 ncpus=2) task:modprobe state:R running task stack:23688 pid:12212 tgid:12212 ppid:12 task_flags:0x400000 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 9b 98 fa 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000ea072b0 EFLAGS: 00000206 RAX: 11a091caad299c00 RBX: 0000000000000202 RCX: 11a091caad299c00 RDX: 0000000000000001 RSI: ffffffff8db48dd1 RDI: ffffffff8be1a180 RBP: ffff88802a3f0b18 R08: 0000000000000022 R09: ffffffff81728e15 R10: ffffc9000ea07438 R11: ffffffff81ace730 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e13f140 R15: ffff88802a3f0000 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_clone+0xb8/0x4f0 mm/rmap.c:288 __split_vma+0x371/0x9b0 mm/vma.c:526 split_vma mm/vma.c:582 [inline] vma_modify+0x9db/0x1970 mm/vma.c:1627 vma_modify_flags+0x1e8/0x230 mm/vma.c:1645 mprotect_fixup+0x400/0x9b0 mm/mprotect.c:658 do_mprotect_pkey+0x8cd/0xce0 mm/mprotect.c:832 __do_sys_mprotect mm/mprotect.c:853 [inline] __se_sys_mprotect mm/mprotect.c:850 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:850 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde542582c7 RSP: 002b:00007ffc5ebe70e8 EFLAGS: 00000206 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 00007fde5422c0c0 RCX: 00007fde542582c7 RDX: 0000000000000001 RSI: 0000000000003000 RDI: 00007fde54228000 RBP: 00007ffc5ebe73b0 R08: 0000000000000000 R09: 00007fde541a9bf7 R10: 00007fde5422c0c0 R11: 0000000000000206 R12: 0000000000000008 R13: 00000149dfc14de4 R14: 0000000000000000 R15: 00007fde5426c310 rcu: rcu_preempt kthread starved for 2308 jiffies! g50073 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:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 12209 Comm: syz.1.1949 Not tainted 6.15.0-syzkaller-11173-g546b1c9e93c2 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 fa 47 3e f6 48 89 df e8 52 df 3e f6 e8 bd eb 67 f6 fb bf 01 00 00 00 62 d9 30 f6 65 8b 05 3b e3 38 07 85 c0 74 07 5b c3 cc cc cc cc RSP: 0018:ffffc9000e967c78 EFLAGS: 00000286 RAX: 3d671b7a6c0c7c00 RBX: ffff8880351b65c0 RCX: 3d671b7a6c0c7c00 RDX: 0000000000000000 RSI: ffffffff8d95cd79 RDI: 0000000000000001 RBP: ffff8880351b6858 R08: ffffffff8f9fb8f7 R09: 1ffffffff1f3f71e R10: dffffc0000000000 R11: fffffbfff1f3f71f R12: 1ffff11006a36d0b R13: 0000000000000000 R14: 0000000004000000 R15: 0000000000000011 FS: 00007fb409bab6c0(0000) GS:ffff888125d93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f957f97d2d8 CR3: 00000000610be000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x117b/0x1310 kernel/signal.c:3037 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb408d8e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb409bab038 EFLAGS: 00000246 RAX: 000000000000000b RBX: 00007fb408fb5fa0 RCX: 00007fb408d8e969 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007fb408e10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb408fb5fa0 R15: 00007ffda705e698