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BUG: KASAN: use-after-free in sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff88805a8eb1ce by task syz.1.78/5466

CPU: 0 UID: 0 PID: 5466 Comm: syz.1.78 Not tainted 6.10.0-rc5-next-20240624-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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
 sysv_new_inode+0xfd3/0x1170 fs/sysv/ialloc.c:153
 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53
 vfs_create+0x23c/0x3d0 fs/namei.c:3218
 do_mknodat+0x447/0x5b0 fs/namei.c:4076
 __do_sys_mknodat fs/namei.c:4104 [inline]
 __se_sys_mknodat fs/namei.c:4101 [inline]
 __x64_sys_mknodat+0xa7/0xc0 fs/namei.c:4101
 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: 0033:0x7fb5c1f75d39
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:00007fb5c19ff048 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007fb5c2103fa0 RCX: 00007fb5c1f75d39
RDX: 0000000000000000 RSI: 0000000020002440 RDI: 0000000000000004
RBP: 00007fb5c1ff6766 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000702 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fb5c2103fa0 R15: 00007fff28a26048
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x6c3f9 pfn:0x5a8eb
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 000000000006c3f9 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 5466, tgid 5465 (syz.1.78), ts 687325309643, free_ts 754749952530
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x2ccb/0x2d80 mm/page_alloc.c:3487
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4745
 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: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_one_qstr_excl+0x11f/0x260 fs/namei.c:1614
 filename_create+0x297/0x540 fs/namei.c:3918
 do_mknodat+0x18b/0x5b0 fs/namei.c:4063
 __do_sys_mknodat fs/namei.c:4104 [inline]
 __se_sys_mknodat fs/namei.c:4101 [inline]
 __x64_sys_mknodat+0xa7/0xc0 fs/namei.c:4101
 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 5466 tgid 5465 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1093 [inline]
 free_unref_folios+0x103a/0x1b00 mm/page_alloc.c:2699
 shrink_folio_list+0x3276/0x8ce0 mm/vmscan.c:1463
 evict_folios+0xb2b/0x2700 mm/vmscan.c:4568
 try_to_shrink_lruvec+0x9ab/0xbb0 mm/vmscan.c:4764
 lru_gen_shrink_lruvec mm/vmscan.c:4907 [inline]
 shrink_lruvec+0x551/0x3070 mm/vmscan.c:5684
 shrink_node_memcgs mm/vmscan.c:5920 [inline]
 shrink_node+0xb1f/0x4160 mm/vmscan.c:5960
 shrink_zones mm/vmscan.c:6204 [inline]
 do_try_to_free_pages+0x78c/0x1cf0 mm/vmscan.c:6266
 try_to_free_mem_cgroup_pages+0x48f/0xb10 mm/vmscan.c:6598
 try_charge_memcg+0x704/0x1850 mm/memcontrol.c:2946
 try_charge mm/memcontrol.c:3094 [inline]
 charge_memcg+0xa2/0x160 mm/memcontrol.c:7530
 __mem_cgroup_charge+0x27/0x80 mm/memcontrol.c:7545
 mem_cgroup_charge include/linux/memcontrol.h:692 [inline]
 filemap_add_folio+0xb3/0x650 mm/filemap.c:965
 do_read_cache_folio+0x10a/0x820 mm/filemap.c:3756
 do_read_cache_page+0x30/0x200 mm/filemap.c:3855
 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:
 ffff88805a8eb080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805a8eb100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805a8eb180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88805a8eb200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805a8eb280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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