rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P12678/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=65857, q=508 ncpus=2)
task:udevd           state:R  running task     stack:21856 pid:12678 tgid:12678 ppid:5194   task_flags:0x400140 flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline]
RIP: 0010:lock_release+0x4d/0x3e0 kernel/locking/lockdep.c:5879
Code: 24 28 0f 1f 44 00 00 65 8b 05 23 8d f3 10 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 4c 57 00 0e 73 16 e8 a5 ea 08 00 84 c0 <75> 0d f6 05 7c 63 ea 0d 01 0f 84 ad 02 00 00 83 3d 4d 87 00 0e 00
RSP: 0018:ffffc9000b56ee30 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff903b0a01 RCX: d1fbac7dc5a36400
RDX: ffffc9000b56ef01 RSI: ffffffff8bc073c0 RDI: ffffffff8bc07380
RBP: dffffc0000000000 R08: ffffc9000b56fe10 R09: ffffc9000b56efb8
R10: dffffc0000000000 R11: fffff520016addf9 R12: ffffc9000b56fe20
R13: ffffffff8173cd25 R14: ffffffff8e13d2e0 R15: ffffffff8173cd25
 rcu_lock_release include/linux/rcupdate.h:341 [inline]
 rcu_read_unlock include/linux/rcupdate.h:897 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1195 [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:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:342 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4962 [inline]
 slab_alloc_node mm/slub.c:5272 [inline]
 kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5279
 anon_vma_chain_alloc mm/rmap.c:141 [inline]
 __anon_vma_prepare+0xcb/0x4a0 mm/rmap.c:194
 __vmf_anon_prepare mm/memory.c:3633 [inline]
 vmf_anon_prepare mm/internal.h:432 [inline]
 do_anonymous_page mm/memory.c:5178 [inline]
 do_pte_missing mm/memory.c:4359 [inline]
 handle_pte_fault mm/memory.c:6177 [inline]
 __handle_mm_fault+0x4aff/0x5400 mm/memory.c:6318
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
 do_user_addr_fault+0x764/0x1380 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x82/0x100 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
RIP: 0010:copy_to_user_iter lib/iov_iter.c:25 [inline]
RIP: 0010:iterate_ubuf include/linux/iov_iter.h:30 [inline]
RIP: 0010:iterate_and_advance2 include/linux/iov_iter.h:302 [inline]
RIP: 0010:iterate_and_advance include/linux/iov_iter.h:330 [inline]
RIP: 0010:_copy_to_iter+0x24a/0x1790 lib/iov_iter.c:185
Code: f1 01 00 00 e8 b7 98 31 fd 48 8b 5c 24 70 48 89 df 4c 8b 7c 24 28 44 89 fe e8 32 4b 97 fd 0f 01 cb 4c 89 f9 48 89 de 4c 89 ef <f3> a4 0f 1f 00 0f 01 ca 4c 89 f3 49 29 cf 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc9000b56f7e0 EFLAGS: 00050246
RAX: ffffffff848eab01 RBX: ffff888064b3d200 RCX: 0000000000000200
RDX: 0000000000000000 RSI: ffff888064b3d200 RDI: 00007f4c4dc60000
RBP: ffffc9000b56f948 R08: ffff888064b3d3ff R09: 1ffff1100c967a7f
R10: dffffc0000000000 R11: ffffed100c967a80 R12: 1ffff920016adfaf
R13: 00007f4c4dc60000 R14: ffffc9000b56fd88 R15: 0000000000000200
 copy_page_to_iter+0x10c/0x1c0 lib/iov_iter.c:362
 copy_folio_to_iter include/linux/uio.h:204 [inline]
 filemap_read+0x7c0/0x11a0 mm/filemap.c:2799
 blkdev_read_iter+0x30a/0x440 block/fops.c:859
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0x55a/0xa30 fs/read_write.c:572
 ksys_read+0x145/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4c4d4a7407
RSP: 002b:00007fff333bf650 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f4c4dc6f880 RCX: 00007f4c4d4a7407
RDX: 0000000000000200 RSI: 00007f4c4dc60000 RDI: 0000000000000009
RBP: 000055df2b840770 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000007fa4200 R14: 000055df2b848888 R15: 00007f4c4dd9639c
 </TASK>
rcu: rcu_preempt kthread starved for 10107 jiffies! g65857 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:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 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+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 5e c3 c3 f5 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 b1 1b 00 f3 0f 1e fa fb f4 <e9> 33 c3 c3 f5 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: c05ae30a03c63400 RBX: ffffffff8196bc07 RCX: c05ae30a03c63400
RDX: 0000000000000001 RSI: ffffffff8d7e7f1e RDI: ffffffff8bc073e0
RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb
R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9dfa70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff110037dbb58
FS:  0000000000000000(0000) GS:ffff888125e0d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000039000 CR3: 0000000078626000 CR4: 0000000000350ef0
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:190 [inline]
 do_idle+0x1e7/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>