loop0: detected capacity change from 0 to 1024
EXT4-fs (loop0): stripe (3) is not aligned with cluster size (16), stripe is disabled
EXT4-fs (loop0): can't mount with data=, fs mounted w/o journal
loop0: detected capacity change from 0 to 128
VFS: Found a Xenix FS (block size = 1024) on device loop0
==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff888041f651ce by task syz.0.0/5315

CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted 6.13.0-rc3-syzkaller-00136-g8faabc041a00 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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
 lookup_open fs/namei.c:3649 [inline]
 open_last_lookups fs/namei.c:3748 [inline]
 path_openat+0x1c03/0x3590 fs/namei.c:3984
 do_filp_open+0x27f/0x4e0 fs/namei.c:4014
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402
 do_sys_open fs/open.c:1417 [inline]
 __do_sys_openat fs/open.c:1433 [inline]
 __se_sys_openat fs/open.c:1428 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1428
 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: 0033:0x7fb316585d29
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:00007fb3172ec038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb316775fa0 RCX: 00007fb316585d29
RDX: 0000000000101042 RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007fb316601aa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb316775fa0 R15: 00007fff08bb1038
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x4f pfn:0x41f65
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea000107d988 ffffea000107d908 0000000000000000
raw: 000000000000004f 0000000000000000 00000000ffffffff 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 5315, tgid 5314 (syz.0.0), ts 76542433653, free_ts 76601092251
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2269
 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2287
 shmem_alloc_folio mm/shmem.c:1794 [inline]
 shmem_alloc_and_add_folio+0x4a0/0x1080 mm/shmem.c:1833
 shmem_get_folio_gfp+0x621/0x1840 mm/shmem.c:2355
 shmem_get_folio mm/shmem.c:2461 [inline]
 shmem_write_begin+0x165/0x350 mm/shmem.c:3117
 generic_perform_write+0x346/0x990 mm/filemap.c:4055
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3293
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:679
 ksys_write+0x18f/0x2b0 fs/read_write.c:731
 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 5315 tgid 5314 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_folios+0xe39/0x18b0 mm/page_alloc.c:2704
 folios_put_refs+0x76c/0x860 mm/swap.c:962
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x593/0x1820 mm/shmem.c:1040
 shmem_truncate_range mm/shmem.c:1152 [inline]
 shmem_evict_inode+0x29b/0xa80 mm/shmem.c:1280
 evict+0x4e8/0x9a0 fs/inode.c:796
 __dentry_kill+0x20d/0x630 fs/dcache.c:625
 dput+0x19f/0x2b0 fs/dcache.c:867
 __fput+0x5ba/0xa50 fs/file_table.c:458
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888041f65080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888041f65100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888041f65180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888041f65200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888041f65280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================