rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6174/1:b..l rcu: (detected by 0, t=10502 jiffies, g=14109, q=900 ncpus=2) task:udevd state:R running task stack:24376 pid:6174 tgid:6174 ppid:5201 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_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline] RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline] RIP: 0010:unwind_next_frame+0x1a68/0x23d0 arch/x86/kernel/unwind_orc.c:695 Code: 01 4c 8b 7c 24 50 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 35 02 00 00 41 c7 06 00 00 00 00 31 db e8 1c bf f2 09 85 c0 74 3a 43 4e 33 00 84 c0 75 31 e8 0a bf f2 09 85 c0 74 28 80 3d 90 3a RSP: 0018:ffffc90003d3f458 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff905c4001 RCX: ffff88802a12bd00 RDX: ffffc90003d3f501 RSI: dffffc0000000000 RDI: ffffc90003d3f530 RBP: dffffc0000000000 R08: ffffc90003d3f650 R09: 0000000000000000 R10: ffffc90003d3f578 R11: fffff520007a7eb1 R12: ffffc90003d3f660 R13: ffffc90003d38000 R14: ffffc90003d3f528 R15: ffffffff81746f85 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_realpath_from_path+0x598/0x5d0 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 security_inode_getattr+0x12f/0x330 security/security.c:1869 vfs_getattr fs/stat.c:259 [inline] vfs_statx_path fs/stat.c:299 [inline] vfs_statx+0x18e/0x550 fs/stat.c:356 vfs_fstatat+0x118/0x170 fs/stat.c:375 __do_sys_newfstatat fs/stat.c:542 [inline] __se_sys_newfstatat fs/stat.c:536 [inline] __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536 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: 0033:0x7f873bf11b0a RSP: 002b:00007fff5deb7b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 00007f873bf11b0a RDX: 00007fff5deb7b40 RSI: 00007fff5deb7c10 RDI: 00000000ffffff9c RBP: 00007fff5deb8c50 R08: 0000000000000064 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff5deb8c60 R13: 0000000000000000 R14: 0000000000000008 R15: 000055803f66b650 rcu: rcu_preempt kthread starved for 9717 jiffies! g14109 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:27896 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: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 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 33 0e 21 00 f3 0f 1e fa fb f4 48 ee 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8e007d80 EFLAGS: 000002c6 RAX: 9135ce5b1ded3d00 RBX: ffffffff8197c6ba RCX: 9135ce5b1ded3d00 RDX: 0000000000000001 RSI: ffffffff8daa9dc3 RDI: ffffffff8be247e0 RBP: ffffffff8e007ea8 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fc3d070 R13: 1ffffffff1c129b8 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881259dc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000fd4630 CR3: 000000007e154000 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+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:758 start_kernel+0x3ac/0x400 init/main.c:1208 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