rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5951/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=31217, q=36348 ncpus=2)
task:udevd           state:R  running task     stack:21888 pid:5951  tgid:5951  ppid:5194   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14ed/0x5040 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:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline]
RIP: 0010:unwind_next_frame+0x51a/0x23d0 arch/x86/kernel/unwind_orc.c:510
Code: 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 49 63 07 <4c> 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 8d 47 fc 48 0f 47 d8
RSP: 0018:ffffc90004a67718 EFLAGS: 00000246
RAX: fffffffff2434322 RBX: ffffffff8fc1a2dc RCX: dffffc0000000000
RDX: ffffffff8fc1a2dc RSI: ffffffff90418aa8 RDI: ffffffff8be08580
RBP: ffffffff8fc1a2dc R08: 0000000000000001 R09: ffffffff8e13efa0
R10: ffffc90004a67838 R11: ffffffff81acb3b0 R12: ffffffff8204e936
R13: ffffffff8fc1a2dc R14: ffffc90004a677e8 R15: ffffffff8fc1a2dc
 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
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5267 [inline]
 kmem_cache_alloc_lru_noprof+0x36c/0x6e0 mm/slub.c:5286
 shmem_alloc_inode+0x28/0x40 mm/shmem.c:5135
 alloc_inode+0x6a/0x1b0 fs/inode.c:346
 new_inode+0x22/0x170 fs/inode.c:1175
 __shmem_get_inode mm/shmem.c:3051 [inline]
 shmem_get_inode+0x347/0xe60 mm/shmem.c:3125
 shmem_mknod+0x191/0x360 mm/shmem.c:3855
 shmem_mkdir+0x33/0x70 mm/shmem.c:3916
 vfs_mkdir+0x414/0x630 fs/namei.c:5196
 do_mkdirat+0x276/0x500 fs/namei.c:5230
 __do_sys_mkdir fs/namei.c:5257 [inline]
 __se_sys_mkdir fs/namei.c:5255 [inline]
 __x64_sys_mkdir+0x6c/0x80 fs/namei.c:5255
 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: 0033:0x7fbd12514c37
RSP: 002b:00007ffed7417408 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffed741910e RCX: 00007fbd12514c37
RDX: 000000000000002d RSI: 00000000000001ed RDI: 00007ffed7417410
RBP: 00007ffed74184b0 R08: 00007ffed7419100 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffed74190e0
R13: 0000000000000000 R14: 000055e1fc51a7d4 R15: 000000000000002d
 </TASK>
rcu: rcu_preempt kthread starved for 10330 jiffies! g31217 f0x2 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:27712 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5282 [inline]
 __schedule+0x14ed/0x5040 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
 </TASK>
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 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 43 5e 2b 00 f3 0f 1e fa fb f4 <c3> 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: 000000000062989b RBX: ffffffff8197171e RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8d99f7ca RDI: ffffffff8be085e0
RBP: ffffffff8de07eb0 R08: ffff8880b863375b R09: 1ffff110170c66eb
R10: dffffc0000000000 R11: ffffed10170c66ec R12: ffffffff8fa24670
R13: 1ffffffff1bd29b8 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125c0a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f29ef24d943 CR3: 000000007dc9c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 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:757
 start_kernel+0x386/0x3d0 init/main.c:1207
 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
 </TASK>