loop4: detected capacity change from 0 to 128
VFS: Found a Xenix FS (block size = 1024) on device loop4
syz.4.5273: attempt to access beyond end of device
loop4: rw=0, sector=6491536, nr_sectors = 2 limit=128
Buffer I/O error on dev loop4, logical block 3245768, async page read
==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff8880586b51ce by task syz.4.5273/19333

CPU: 0 UID: 0 PID: 19333 Comm: syz.4.5273 Not tainted 6.13.0-rc3-next-20241220-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
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:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153
 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4189
 do_mknodat+0x3ec/0x5b0
 __do_sys_mknod fs/namei.c:4272 [inline]
 __se_sys_mknod fs/namei.c:4270 [inline]
 __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4270
 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
RIP: 0033:0x7f811e185d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f811f072038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f811e375fa0 RCX: 00007f811e185d29
RDX: 0000000000000000 RSI: 000000000000c000 RDI: 0000000020000040
RBP: 00007f811e201aa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f811e375fa0 R15: 00007ffd06180818
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x7fcbc256f pfn:0x586b5
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea000126f508 ffffea0001568088 0000000000000000
raw: 00000007fcbc256f 0000000000000000 00000000f0000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO), pid 19328, tgid 19328 (syz.0.5274), ts 444779644067, free_ts 444894360280
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4754
 alloc_pages_mpol+0x30e/0x550 mm/mempolicy.c:2270
 folio_alloc_mpol_noprof mm/mempolicy.c:2288 [inline]
 vma_alloc_folio_noprof+0x12b/0x260 mm/mempolicy.c:2323
 folio_prealloc+0x2e/0x170
 wp_page_copy mm/memory.c:3436 [inline]
 do_wp_page+0x1253/0x49b0 mm/memory.c:3828
 handle_pte_fault+0xfa5/0x5ee0 mm/memory.c:5906
 __handle_mm_fault mm/memory.c:6033 [inline]
 handle_mm_fault+0x11f5/0x1d50 mm/memory.c:6202
 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
page last free pid 19328 tgid 19328 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_folios+0xe40/0x18b0 mm/page_alloc.c:2707
 folios_put_refs+0x76c/0x860 mm/swap.c:990
 free_pages_and_swap_cache+0x5c8/0x690 mm/swap_state.c:335
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:373 [inline]
 tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:380
 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:472
 exit_mmap+0x52f/0xd50 mm/mmap.c:1357
 __mmput+0x115/0x420 kernel/fork.c:1345
 exit_mm+0x220/0x310 kernel/exit.c:570
 do_exit+0x9b2/0x28e0 kernel/exit.c:925
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 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

Memory state around the buggy address:
 ffff8880586b5080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880586b5100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880586b5180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8880586b5200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880586b5280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================