REISERFS warning (device loop2): vs-13060 reiserfs_update_sd_size: stat data of object [3 6 0x0 SD] (nlink == 2) not found (pos 1)
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BUG: KASAN: use-after-free in bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
BUG: KASAN: use-after-free in search_by_entry_key+0x597/0x1370 fs/reiserfs/namei.c:165
Read of size 4 at addr ffff88804bc61fc4 by task syz.2.395/5572

CPU: 1 PID: 5572 Comm: syz.2.395 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x200 mm/kasan/report.c:418
 kasan_report+0x10b/0x140 mm/kasan/report.c:522
 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
 search_by_entry_key+0x597/0x1370 fs/reiserfs/namei.c:165
 reiserfs_find_entry+0x2ff/0x18e0 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x1a7/0x420 fs/reiserfs/namei.c:368
 __lookup_slow+0x27d/0x3a0 fs/namei.c:1690
 lookup_one_len+0x18e/0x2c0 fs/namei.c:2740
 open_xa_dir+0x46b/0x6f0 fs/reiserfs/xattr.c:162
 xattr_lookup+0x22/0x2a0 fs/reiserfs/xattr.c:395
 reiserfs_xattr_set_handle+0xf3/0xca0 fs/reiserfs/xattr.c:533
 reiserfs_xattr_set+0x435/0x550 fs/reiserfs/xattr.c:633
 __vfs_setxattr+0x3e0/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x129/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x168/0x2f0 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x2b2/0x2d0 fs/xattr.c:617
 path_setxattr+0x142/0x280 fs/xattr.c:636
 __do_sys_lsetxattr fs/xattr.c:659 [inline]
 __se_sys_lsetxattr fs/xattr.c:655 [inline]
 __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:655
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa899f8e9a9
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:00007fa89ae16038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fa89a1b6080 RCX: 00007fa899f8e9a9
RDX: 0000200000000400 RSI: 00002000000000c0 RDI: 0000200000000080
RBP: 00007fa89a010d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000104 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa89a1b6080 R15: 00007ffec10a8a68
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00012f1840 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x4bc61
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000001 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 5513, tgid 5512 (syz.0.389), ts 130367583543, free_ts 132652432987
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532
 prep_new_page mm/page_alloc.c:2539 [inline]
 get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328
 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614
 __folio_alloc+0xe/0x30 mm/page_alloc.c:5646
 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243
 shmem_alloc_folio mm/shmem.c:1589 [inline]
 shmem_alloc_and_acct_folio+0x42e/0xb60 mm/shmem.c:1613
 shmem_get_folio_gfp+0x1361/0x3400 mm/shmem.c:1941
 shmem_get_folio mm/shmem.c:2072 [inline]
 shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556
 generic_perform_write+0x2db/0x560 mm/filemap.c:3846
 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974
 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x44c/0x960 fs/read_write.c:584
 ksys_write+0x143/0x240 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1459 [inline]
 free_pcp_prepare mm/page_alloc.c:1509 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3525
 release_pages+0x1f92/0x2200 mm/swap.c:1035
 __pagevec_release+0x6d/0xe0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x75b/0x2050 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x248/0xa40 mm/shmem.c:1171
 evict+0x485/0x870 fs/inode.c:705
 __dentry_kill+0x431/0x650 fs/dcache.c:611
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xfa/0x1d0 fs/dcache.c:918
 __fput+0x5e0/0x920 fs/file_table.c:328
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87

Memory state around the buggy address:
 ffff88804bc61e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804bc61f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804bc61f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88804bc62000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804bc62080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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