==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff8880525fe1ce by task syz.4.110/5643

CPU: 0 PID: 5643 Comm: syz.4.110 Not tainted 6.10.0-rc6-syzkaller-00163-g661e504db04c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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
 sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53
 lookup_open fs/namei.c:3505 [inline]
 open_last_lookups fs/namei.c:3574 [inline]
 path_openat+0x1a86/0x35f0 fs/namei.c:3810
 do_filp_open+0x235/0x490 fs/namei.c:3840
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1413
 do_sys_open fs/open.c:1428 [inline]
 __do_sys_open fs/open.c:1436 [inline]
 __se_sys_open fs/open.c:1432 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1432
 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: 0033:0x7fd8a3175bd9
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:00007fd8a3fc9048 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fd8a3303f60 RCX: 00007fd8a3175bd9
RDX: 0000000000000000 RSI: 0000000000060840 RDI: 00000000209e1000
RBP: 00007fd8a31e4aa1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd8a3303f60 R15: 00007ffff62b4be8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x63e02 pfn:0x525fe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000063e02 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 5643, tgid 5642 (syz.4.110), ts 682223679385, free_ts 743103921787
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1473
 prep_new_page mm/page_alloc.c:1481 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3425
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4683
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_pages_noprof mm/mempolicy.c:2336 [inline]
 folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2343
 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1008
 do_read_cache_folio+0xed/0x820 mm/filemap.c:3752
 do_read_cache_page+0x30/0x200 mm/filemap.c:3854
 read_mapping_page include/linux/pagemap.h:900 [inline]
 dir_get_page fs/sysv/dir.c:64 [inline]
 sysv_find_entry+0x1af/0x410 fs/sysv/dir.c:157
 sysv_inode_by_name+0x98/0x1f0 fs/sysv/dir.c:374
 sysv_lookup+0x6b/0xe0 fs/sysv/namei.c:38
 lookup_open fs/namei.c:3483 [inline]
 open_last_lookups fs/namei.c:3574 [inline]
 path_openat+0x11c2/0x35f0 fs/namei.c:3810
 do_filp_open+0x235/0x490 fs/namei.c:3840
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1413
 do_sys_open fs/open.c:1428 [inline]
 __do_sys_open fs/open.c:1436 [inline]
 __se_sys_open fs/open.c:1432 [inline]
 __x64_sys_open+0x225/0x270 fs/open.c:1432
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
page last free pid 5643 tgid 5642 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1093 [inline]
 free_unref_folios+0xf23/0x19e0 mm/page_alloc.c:2637
 shrink_folio_list+0x33cd/0x8f70 mm/vmscan.c:1446
 evict_folios+0xb2e/0x2710 mm/vmscan.c:4553
 try_to_shrink_lruvec+0xb6b/0xe90 mm/vmscan.c:4749
 lru_gen_shrink_lruvec mm/vmscan.c:4892 [inline]
 shrink_lruvec+0x586/0x2f90 mm/vmscan.c:5669
 shrink_node_memcgs mm/vmscan.c:5889 [inline]
 shrink_node+0xa18/0x3fe0 mm/vmscan.c:5924
 shrink_zones mm/vmscan.c:6168 [inline]
 do_try_to_free_pages+0x77d/0x1c40 mm/vmscan.c:6230
 try_to_free_mem_cgroup_pages+0x465/0xac0 mm/vmscan.c:6545
 try_charge_memcg+0x701/0x1840 mm/memcontrol.c:2944
 try_charge mm/memcontrol.c:3092 [inline]
 charge_memcg+0xa2/0x160 mm/memcontrol.c:7495
 __mem_cgroup_charge+0x27/0x80 mm/memcontrol.c:7510
 mem_cgroup_charge include/linux/memcontrol.h:691 [inline]
 filemap_add_folio+0xb3/0x650 mm/filemap.c:965
 do_read_cache_folio+0x10a/0x820 mm/filemap.c:3755
 do_read_cache_page+0x30/0x200 mm/filemap.c:3854
 read_mapping_page include/linux/pagemap.h:900 [inline]
 dir_get_page fs/sysv/dir.c:64 [inline]
 sysv_find_entry+0x1af/0x410 fs/sysv/dir.c:157
 sysv_inode_by_name+0x98/0x1f0 fs/sysv/dir.c:374

Memory state around the buggy address:
 ffff8880525fe080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880525fe100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8880525fe180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8880525fe200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880525fe280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================