BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 800000002a885067 P4D 800000002a885067 PUD 29809067 PMD 0 
Oops: Oops: 0010 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 5490 Comm: syz.0.44 Not tainted 6.11.0-rc4-next-20240821-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc900045b7d00 EFLAGS: 00010046
==================================================================
BUG: KASAN: stack-out-of-bounds in __show_regs+0xdc/0x610 arch/x86/kernel/process_64.c:83
Read of size 8 at addr ffffc900045b7cb0 by task syz.0.44/5490

CPU: 0 UID: 0 PID: 5490 Comm: syz.0.44 Not tainted 6.11.0-rc4-next-20240821-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __show_regs+0xdc/0x610 arch/x86/kernel/process_64.c:83
 show_regs arch/x86/kernel/dumpstack.c:472 [inline]
 __die_body+0x3c/0xb0 arch/x86/kernel/dumpstack.c:420
 page_fault_oops+0x8e4/0xcc0 arch/x86/mm/fault.c:711
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x5ed/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffffc900045b7d00 EFLAGS: 00010046
RAX: ffff88807ad35a00 RBX: 1ffff920008b6fac RCX: 1ffff920008b6f60
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff81324838 R09: 1ffff110039e73c0
R10: dffffc0000000000 R11: ffffed10039e73c1 R12: 1ffff11003e842c0
R13: 0000000000000046 R14: 0000000000000046 R15: 0000000000000000
 </TASK>

The buggy address belongs to stack of task syz.0.44/5490
 and is located at offset 496 in frame:
 page_fault_oops+0x0/0xcc0

This frame has 7 objects:
 [32, 36) 'level.i'
 [48, 49) 'nx.i'
 [64, 65) 'rw.i'
 [80, 90) 'idt.i'
 [112, 122) 'gdt.i'
 [144, 146) 'ldtr.i'
 [160, 192) 'info'

The buggy address belongs to the virtual mapping at
 [ffffc900045b0000, ffffc900045b9000) created by:
 copy_process+0x5d1/0x3d50 kernel/fork.c:2206

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x4 pfn:0x62fa9
memcg:ffff88802ce89582
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000004 0000000000000000 00000001ffffffff ffff88802ce89582
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 5411, tgid 5411 (syz.1.31), ts 88409263333, free_ts 88406963467
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1517
 prep_new_page mm/page_alloc.c:1525 [inline]
 get_page_from_freelist+0x3004/0x30c0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x29e/0x780 mm/page_alloc.c:4743
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 vm_area_alloc_pages mm/vmalloc.c:3600 [inline]
 __vmalloc_area_node mm/vmalloc.c:3669 [inline]
 __vmalloc_node_range_noprof+0xa40/0x1400 mm/vmalloc.c:3850
 alloc_thread_stack_node kernel/fork.c:314 [inline]
 dup_task_struct+0x444/0x8c0 kernel/fork.c:1115
 copy_process+0x5d1/0x3d50 kernel/fork.c:2206
 kernel_clone+0x226/0x8f0 kernel/fork.c:2787
 __do_sys_clone3 kernel/fork.c:3091 [inline]
 __se_sys_clone3+0x2cb/0x350 kernel/fork.c:3070
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5411 tgid 5411 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1098 [inline]
 free_unref_page+0xc07/0xd90 mm/page_alloc.c:2651
 __slab_free+0x31b/0x3d0 mm/slub.c:4432
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4036 [inline]
 slab_alloc_node mm/slub.c:4085 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4092
 anon_vma_chain_alloc mm/rmap.c:143 [inline]
 __anon_vma_prepare+0xc4/0x4a0 mm/rmap.c:196
 vmf_anon_prepare mm/memory.c:3289 [inline]
 do_anonymous_page mm/memory.c:4549 [inline]
 do_pte_missing mm/memory.c:3945 [inline]
 handle_pte_fault+0x534f/0x67c0 mm/memory.c:5522
 __handle_mm_fault mm/memory.c:5665 [inline]
 handle_mm_fault+0x1029/0x1980 mm/memory.c:5833
 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

Memory state around the buggy address:
 ffffc900045b7b80: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900045b7c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900045b7c80: 00 00 00 00 00 00 f3 f3 00 00 00 00 00 00 00 00
                                     ^
 ffffc900045b7d00: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
 ffffc900045b7d80: 04 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================