rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7844/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=26325, q=676 ncpus=2)
task:udevd state:R running task stack:27464 pid:7844 tgid:7844 ppid:5233 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lookup_page_ext mm/page_ext.c:252 [inline]
RIP: 0010:page_ext_lookup+0xd5/0x180 mm/page_ext.c:509
Code: 83 e3 7f c1 e3 05 49 01 de eb 0f e8 75 88 91 ff eb 05 e8 6e 88 91 ff 45 31 f6 49 83 c6 10 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 f7 e8 f1 e6 f4 ff 49 8b 1e e8 f9 0b 77 ff 89 c5 31 ff
RSP: 0018:ffffc9001dc8f2d0 EFLAGS: 00000246
RAX: 1ffff11027fff4a6 RBX: 0000000000000120 RCX: ffff888030295a00
RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000000000000000
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff822e2bea
R10: dffffc0000000000 R11: ffffed100abce4ba R12: 000000000004fd59
R13: dffffc0000000000 R14: ffff88813fffa530 R15: 0000000000001000
page_ext_iter_begin include/linux/page_ext.h:132 [inline]
__page_table_check_zero+0x18f/0x530 mm/page_table_check.c:139
page_table_check_free include/linux/page_table_check.h:43 [inline]
free_pages_prepare mm/page_alloc.c:1396 [inline]
__free_frozen_pages+0xbd7/0xd30 mm/page_alloc.c:2895
__slab_free+0x303/0x3c0 mm/slub.c:4591
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:385
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4365 [inline]
__kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4377
kmalloc_noprof include/linux/slab.h:909 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x1c1/0x3b0 security/tomoyo/file.c:771
security_file_open+0xb1/0x270 security/security.c:3144
do_dentry_open+0x384/0x13f0 fs/open.c:942
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
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: 0033:0x7fbadfea7407
RSP: 002b:00007ffdc989b690 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbae0599880 RCX: 00007fbadfea7407
RDX: 00000000000a0800 RSI: 000056309c748670 RDI: ffffffffffffff9c
RBP: 000056309c737910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056309c74fe20
R13: 000056309c74f430 R14: 0000000000000000 R15: 000056309c74fe20
rcu: rcu_preempt kthread starved for 8939 jiffies! g26325 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:27160 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
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+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: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller-11489-gd2eedaa3909b #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 13 e8 02 00 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 53 a7 10 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:ffffffff8de07d80 EFLAGS: 000002c2
RAX: 1064e3614cfe1500 RBX: ffffffff81968218 RCX: 1064e3614cfe1500
RDX: 0000000000000001 RSI: ffffffff8d9b167f RDI: ffffffff8be30500
RBP: ffffffff8de07eb8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3
R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fa33030
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a20
FS: 0000000000000000(0000) GS:ffff888125c28000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9489e46616 CR3: 000000002236c000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:757
default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:190 [inline]
do_idle+0x1e8/0x510 kernel/sched/idle.c:330
cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
rest_init+0x2de/0x300 init/main.c:744
start_kernel+0x3a9/0x410 init/main.c:1097
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
common_startup_64+0x13e/0x147