rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5825/1:b..l rcu: (detected by 1, t=10502 jiffies, g=8565, q=275 ncpus=2) task:udevd state:R running task stack:25240 pid:5825 tgid:5825 ppid:5200 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7193 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x16c/0x340 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 44 41 01 11 <48> 3b 44 24 58 0f 85 e5 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900037970d8 EFLAGS: 00000206 RAX: fd493d1288890600 RBX: 0000000000000000 RCX: fd493d1288890600 RDX: 00000000a8b622a8 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960 RBP: ffffffff81742f85 R08: ffffffff81742f85 R09: ffffffff8e13f2e0 R10: ffffc90003797298 R11: ffffffff81ad9d50 R12: 0000000000000002 R13: ffffffff8e13f2e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 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: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:6674 [inline] kfree+0x1c0/0x660 mm/slub.c:6882 tomoyo_check_open_permission+0x2c2/0x3b0 security/tomoyo/file.c:786 security_file_open+0xb1/0x270 security/security.c:2636 do_dentry_open+0x384/0x14e0 fs/open.c:939 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:4627 [inline] path_openat+0x2de0/0x3840 fs/namei.c:4786 do_filp_open+0x1fa/0x410 fs/namei.c:4813 do_sys_openat2+0x121/0x200 fs/open.c:1391 do_sys_open fs/open.c:1397 [inline] __do_sys_openat fs/open.c:1413 [inline] __se_sys_openat fs/open.c:1408 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1408 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4f639c7407 RSP: 002b:00007ffce6077d60 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f4f6339b880 RCX: 00007f4f639c7407 RDX: 0000000000080241 RSI: 00007ffce60782c0 RDI: ffffffffffffff9c RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000202 R12: 000055718aa5cdfc R13: 000055718aa5cdfc R14: 0000000000000001 R15: 000055718aa77140 rcu: rcu_preempt kthread starved for 10550 jiffies! g8565 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:27728 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 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+0x599/0xb30 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: 5893 Comm: syz-executor228 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:kasan_check_range+0xd/0x2c0 mm/kasan/generic.c:199 Code: 59 c1 ff fe 90 0f 0b cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 41 55 41 54 <53> b0 01 48 85 f6 0f 84 ba 01 00 00 4c 8d 04 37 49 39 f8 0f 82 82 RSP: 0018:ffffc90003f2f530 EFLAGS: 00000246 RAX: ffffffff8146b6b4 RBX: 0000000000000000 RCX: ffffffff8146b6e3 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8880344d8038 RBP: ffffc90003f2f990 R08: ffff8880344d803f R09: 1ffff1100689b007 R10: dffffc0000000000 R11: ffffed100689b008 R12: 1ffff1100689b007 R13: ffff8880344d8000 R14: ffff8880344d8038 R15: dffffc0000000000 FS: 00007f41567de6c0(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f41567bcd58 CR3: 0000000035190000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] kvm_test_request include/linux/kvm_host.h:2279 [inline] kvm_check_request include/linux/kvm_host.h:2289 [inline] vcpu_enter_guest arch/x86/kvm/x86.c:11144 [inline] vcpu_run+0x1ca3/0x76b0 arch/x86/kvm/x86.c:11639 kvm_arch_vcpu_ioctl_run+0x1148/0x1c90 arch/x86/kvm/x86.c:11984 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4492 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+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f415682dc79 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 1d 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f41567de218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f41568b03e8 RCX: 00007f415682dc79 RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005 RBP: 00007f41568b03e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f415687d07c R13: 0000200000000000 R14: 0000200000000140 R15: 0000200000000040