==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff888050a1a1ce by task syz-executor.2/14724

CPU: 1 PID: 14724 Comm: syz-executor.2 Not tainted 6.10.0-rc3-next-20240611-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:91 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:117
 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:3516 [inline]
 open_last_lookups fs/namei.c:3585 [inline]
 path_openat+0x1425/0x3280 fs/namei.c:3815
 do_filp_open+0x235/0x490 fs/namei.c:3845
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1409
 do_sys_open fs/open.c:1424 [inline]
 __do_sys_openat fs/open.c:1440 [inline]
 __se_sys_openat fs/open.c:1435 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1435
 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: 0033:0x7f39c0c7cea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f39c1adf0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f39c0db3f80 RCX: 00007f39c0c7cea9
RDX: 000000000000275a RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007f39c0cebff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000004d R14: 00007f39c0db3f80 R15: 00007ffdabb85588
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x69873 pfn:0x50a1a
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xbfffffff(buddy)
raw: 00fff00000000000 ffffea000100cf88 ffffea00020bbc48 0000000000000000
raw: 0000000000069873 0000000000000000 00000000bfffffff 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 14724, tgid 14723 (syz-executor.2), ts 1466832828846, free_ts 1581599991773
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1470
 prep_new_page mm/page_alloc.c:1478 [inline]
 get_page_from_freelist+0x2cbd/0x2d70 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4715
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263
 alloc_pages_noprof mm/mempolicy.c:2340 [inline]
 folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2347
 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1008
 do_read_cache_folio+0xed/0x820 mm/filemap.c:3753
 do_read_cache_page+0x30/0x200 mm/filemap.c:3855
 read_mapping_page include/linux/pagemap.h:896 [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:3494 [inline]
 open_last_lookups fs/namei.c:3585 [inline]
 path_openat+0x1033/0x3280 fs/namei.c:3815
 do_filp_open+0x235/0x490 fs/namei.c:3845
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1409
 do_sys_open fs/open.c:1424 [inline]
 __do_sys_openat fs/open.c:1440 [inline]
 __se_sys_openat fs/open.c:1435 [inline]
 __x64_sys_openat+0x247/0x2a0 fs/open.c:1435
 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 14724 tgid 14723 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1089 [inline]
 free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2669
 shrink_folio_list+0x3276/0x8ce0 mm/vmscan.c:1464
 evict_folios+0xb2b/0x2700 mm/vmscan.c:4569
 try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4765
 lru_gen_shrink_lruvec mm/vmscan.c:4908 [inline]
 shrink_lruvec+0x551/0x3070 mm/vmscan.c:5685
 shrink_node_memcgs mm/vmscan.c:5921 [inline]
 shrink_node+0xb1f/0x4160 mm/vmscan.c:5961
 shrink_zones mm/vmscan.c:6205 [inline]
 do_try_to_free_pages+0x78c/0x1cf0 mm/vmscan.c:6267
 try_to_free_mem_cgroup_pages+0x48f/0xb10 mm/vmscan.c:6599
 try_charge_memcg+0x704/0x1850 mm/memcontrol.c:2946
 obj_cgroup_charge_pages mm/memcontrol.c:3418 [inline]
 obj_cgroup_charge+0x38a/0x630 mm/memcontrol.c:3707
 __memcg_slab_post_alloc_hook+0x1b1/0x7e0 mm/memcontrol.c:3768
 memcg_slab_post_alloc_hook mm/slub.c:2122 [inline]
 slab_post_alloc_hook mm/slub.c:3980 [inline]
 slab_alloc_node mm/slub.c:4019 [inline]
 kmem_cache_alloc_noprof+0x1de/0x2a0 mm/slub.c:4026
 alloc_buffer_head+0x2a/0x290 fs/buffer.c:3023
 folio_alloc_buffers+0x241/0x5b0 fs/buffer.c:929
 create_empty_buffers+0x3a/0x740 fs/buffer.c:1671
 block_read_full_folio+0x25c/0xcd0 fs/buffer.c:2385

Memory state around the buggy address:
 ffff888050a1a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888050a1a100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888050a1a180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888050a1a200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888050a1a280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================