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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 ffff88808ab8a1ce by task syz-executor.4/16351

CPU: 1 PID: 16351 Comm: syz-executor.4 Not tainted 6.10.0-rc4-syzkaller-00301-g5f583a3162ff #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
 vfs_create+0x23c/0x3d0 fs/namei.c:3207
 do_mknodat+0x447/0x5b0 fs/namei.c:4059
 __do_sys_mknod fs/namei.c:4092 [inline]
 __se_sys_mknod fs/namei.c:4090 [inline]
 __x64_sys_mknod+0x8e/0xa0 fs/namei.c:4090
 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: 0033:0x7f491727d0a9
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:00007f4917f570c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f49173b3f80 RCX: 00007f491727d0a9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020000040
RBP: 00007f49172ec074 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f49173b3f80 R15: 00007ffd6ed7bbf8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x6a630 pfn:0x8ab8a
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 000000000006a630 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 16351, tgid 16350 (syz-executor.4), ts 1321525746758, free_ts 1427026681757
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x2e43/0x2f00 mm/page_alloc.c:3420
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4678
 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_one_qstr_excl+0x11f/0x260 fs/namei.c:1607
 filename_create+0x297/0x540 fs/namei.c:3901
 do_mknodat+0x18b/0x5b0 fs/namei.c:4046
 __do_sys_mknod fs/namei.c:4092 [inline]
 __se_sys_mknod fs/namei.c:4090 [inline]
 __x64_sys_mknod+0x8e/0xa0 fs/namei.c:4090
 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 21390 tgid 21389 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_folios+0xf12/0x19c0 mm/page_alloc.c:2632
 shrink_folio_list+0x85f3/0x9120 mm/vmscan.c:1513
 shrink_inactive_list mm/vmscan.c:1944 [inline]
 shrink_list mm/vmscan.c:2179 [inline]
 shrink_lruvec+0x1663/0x2d90 mm/vmscan.c:5703
 shrink_node_memcgs mm/vmscan.c:5889 [inline]
 shrink_node+0x1081/0x2a30 mm/vmscan.c:5924
 shrink_zones mm/vmscan.c:6168 [inline]
 do_try_to_free_pages+0x695/0x1aa0 mm/vmscan.c:6230
 try_to_free_mem_cgroup_pages+0x47a/0xad0 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]
 shmem_alloc_and_add_folio+0x394/0xdb0 mm/shmem.c:1677
 shmem_get_folio_gfp+0x82d/0x1f50 mm/shmem.c:2055
 shmem_fault+0x252/0x6f0 mm/shmem.c:2255
 __do_fault+0x135/0x460 mm/memory.c:4556
 do_read_fault mm/memory.c:4920 [inline]
 do_fault mm/memory.c:5050 [inline]
 do_pte_missing mm/memory.c:3897 [inline]
 handle_pte_fault+0x3d15/0x7090 mm/memory.c:5380
 __handle_mm_fault mm/memory.c:5523 [inline]
 handle_mm_fault+0xfb0/0x19d0 mm/memory.c:5688
 faultin_page mm/gup.c:1290 [inline]
 __get_user_pages+0x6ef/0x1590 mm/gup.c:1589

Memory state around the buggy address:
 ffff88808ab8a080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88808ab8a100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88808ab8a180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88808ab8a200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88808ab8a280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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