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BUG: KASAN: use-after-free in inode2sd+0x64f/0xa20 fs/reiserfs/inode.c:1364
Write of size 2 at addr ffff888059efe554 by task syz-executor389/13354

CPU: 0 UID: 0 PID: 13354 Comm: syz-executor389 Not tainted 6.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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
 inode2sd+0x64f/0xa20 fs/reiserfs/inode.c:1364
 update_stat_data fs/reiserfs/inode.c:1425 [inline]
 reiserfs_update_sd_size+0xa68/0x10b0 fs/reiserfs/inode.c:1491
 reiserfs_update_sd fs/reiserfs/reiserfs.h:3101 [inline]
 reiserfs_do_truncate+0xe3a/0x1500 fs/reiserfs/stree.c:2035
 reiserfs_truncate_file+0x4c7/0x810 fs/reiserfs/inode.c:2301
 reiserfs_setattr+0xbdd/0x1150 fs/reiserfs/inode.c:3385
 notify_change+0xbca/0xe90 fs/attr.c:503
 do_truncate+0x220/0x310 fs/open.c:65
 handle_truncate fs/namei.c:3395 [inline]
 do_open fs/namei.c:3778 [inline]
 path_openat+0x2e1a/0x3590 fs/namei.c:3933
 do_filp_open+0x235/0x490 fs/namei.c:3960
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
 do_sys_open fs/open.c:1430 [inline]
 __do_sys_creat fs/open.c:1508 [inline]
 __se_sys_creat fs/open.c:1502 [inline]
 __x64_sys_creat+0x123/0x170 fs/open.c:1502
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7fafcf360a99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 1b 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:00007fafcf30e168 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fafcf3e26c8 RCX: 00007fafcf360a99
RDX: 00007fafcf360a99 RSI: 0000000000000000 RDI: 0000000020000940
RBP: 00007fafcf3e26c0 R08: 00007fafcf30e6c0 R09: 0000000000000000
R10: 00007fafcf30e6c0 R11: 0000000000000246 R12: 00007fafcf3e26cc
R13: 0000000000000006 R14: 00007ffc329acd60 R15: 00007ffc329ace48
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x43 pfn:0x59efe
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f0(buddy)
raw: 00fff00000000000 ffffea0001c5de08 ffffea0001c5f008 0000000000000000
raw: 0000000000000043 0000000000000001 00000000f0000000 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 13371, tgid 13355 (syz-executor389), ts 515764069555, free_ts 515774419151
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ee/0x220 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1545 [inline]
 get_page_from_freelist+0x3a55/0x3cc0 mm/page_alloc.c:3457
 __alloc_pages_noprof+0x261/0x6a0 mm/page_alloc.c:4733
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 folio_alloc_mpol_noprof+0x36/0x50 mm/mempolicy.c:2283
 shmem_alloc_folio mm/shmem.c:1769 [inline]
 shmem_alloc_and_add_folio+0x49b/0x13d0 mm/shmem.c:1808
 shmem_get_folio_gfp+0x5a9/0x2090 mm/shmem.c:2330
 shmem_get_folio mm/shmem.c:2436 [inline]
 shmem_write_begin+0x17e/0x460 mm/shmem.c:3041
 generic_perform_write+0x345/0xbf0 mm/filemap.c:4054
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3216
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
page last free pid 13371 tgid 13355 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1108 [inline]
 free_unref_folios+0xed7/0x1870 mm/page_alloc.c:2686
 folios_put_refs+0x76c/0x860 mm/swap.c:1007
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x64c/0x1ce0 mm/shmem.c:1032
 shmem_truncate_range mm/shmem.c:1144 [inline]
 shmem_evict_inode+0x29e/0xa90 mm/shmem.c:1272
 evict+0x4e8/0x9a0 fs/inode.c:725
 __dentry_kill+0x200/0x610 fs/dcache.c:615
 dput+0x19f/0x2b0 fs/dcache.c:857
 __fput+0x5d2/0x880 fs/file_table.c:439
 __do_sys_close fs/open.c:1567 [inline]
 __se_sys_close+0x15f/0x220 fs/open.c:1552
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x82/0x160 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Memory state around the buggy address:
 ffff888059efe400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888059efe480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888059efe500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff888059efe580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888059efe600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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