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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+0x579/0x1380 fs/reiserfs/namei.c:165
Read of size 4 at addr ffff88802c6407c4 by task syz-executor.4/14503

CPU: 1 PID: 14503 Comm: syz-executor.4 Not tainted 6.7.0-rc3-syzkaller-00048-ge8f60209d6cf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x142/0x170 mm/kasan/report.c:588
 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
 search_by_entry_key+0x579/0x1380 fs/reiserfs/namei.c:165
 reiserfs_find_entry+0x2ce/0x19b0 fs/reiserfs/namei.c:322
 reiserfs_lookup+0x1e2/0x580 fs/reiserfs/namei.c:368
 lookup_open fs/namei.c:3455 [inline]
 open_last_lookups fs/namei.c:3546 [inline]
 path_openat+0x1010/0x3290 fs/namei.c:3776
 do_filp_open+0x234/0x490 fs/namei.c:3809
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1440
 do_sys_open fs/open.c:1455 [inline]
 __do_sys_openat fs/open.c:1471 [inline]
 __se_sys_openat fs/open.c:1466 [inline]
 __x64_sys_openat+0x247/0x290 fs/open.c:1466
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f883387cae9
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:00007f88345dc0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f883399bf80 RCX: 00007f883387cae9
RDX: 000000000000275a RSI: 0000000020000600 RDI: ffffffffffffff9c
RBP: 00007f88338c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f883399bf80 R15: 00007ffc5ce236c8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000b19000 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x2c640
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0000b19048 ffffea00023a4cc8 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 14468, tgid 14467 (syz-executor.4), ts 611130509202, free_ts 611870993685
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1544 [inline]
 get_page_from_freelist+0x33ea/0x3570 mm/page_alloc.c:3312
 __alloc_pages+0x255/0x680 mm/page_alloc.c:4568
 alloc_pages_mpol+0x3de/0x640 mm/mempolicy.c:2133
 shmem_alloc_folio mm/shmem.c:1613 [inline]
 shmem_alloc_and_add_folio+0x24f/0xde0 mm/shmem.c:1653
 shmem_get_folio_gfp+0x7c3/0x1ee0 mm/shmem.c:2037
 shmem_get_folio mm/shmem.c:2119 [inline]
 shmem_write_begin+0x170/0x4c0 mm/shmem.c:2702
 generic_perform_write+0x31b/0x630 mm/filemap.c:3918
 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2878
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x792/0xb20 fs/read_write.c:584
 ksys_write+0x1a0/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1137 [inline]
 free_unref_page_prepare+0x931/0xa60 mm/page_alloc.c:2347
 free_unref_page_list+0x5a0/0x840 mm/page_alloc.c:2533
 release_pages+0x2117/0x2400 mm/swap.c:1042
 __folio_batch_release+0x84/0x100 mm/swap.c:1062
 folio_batch_release include/linux/pagevec.h:83 [inline]
 shmem_undo_range+0x6aa/0x19d0 mm/shmem.c:1004
 shmem_truncate_range mm/shmem.c:1096 [inline]
 shmem_evict_inode+0x29b/0xa60 mm/shmem.c:1224
 evict+0x2a4/0x630 fs/inode.c:666
 __dentry_kill+0x436/0x660 fs/dcache.c:607
 dentry_kill+0xbb/0x290
 dput+0x21e/0x470 fs/dcache.c:913
 __fput+0x60b/0xa10 fs/file_table.c:402
 task_work_run+0x24a/0x300 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x150 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x69/0x2a0 kernel/entry/common.c:296
 do_syscall_64+0x52/0x110 arch/x86/entry/common.c:88

Memory state around the buggy address:
 ffff88802c640680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802c640700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88802c640780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88802c640800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88802c640880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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