loop0: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
==================================================================
BUG: KASAN: use-after-free in ocfs2_dir_foreach_blk_id fs/ocfs2/dir.c:1787 [inline]
BUG: KASAN: use-after-free in ocfs2_dir_foreach_blk+0x1344/0x1b30 fs/ocfs2/dir.c:1925
Read of size 2 at addr ffff88805b4d78c9 by task syz.0.17/6174

CPU: 1 UID: 0 PID: 6174 Comm: syz.0.17 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 ocfs2_dir_foreach_blk_id fs/ocfs2/dir.c:1787 [inline]
 ocfs2_dir_foreach_blk+0x1344/0x1b30 fs/ocfs2/dir.c:1925
 ocfs2_readdir+0x2b1/0x5e0 fs/ocfs2/dir.c:1969
 wrap_directory_iterator+0x91/0xd0 fs/readdir.c:65
 iterate_dir+0x5a9/0x760 fs/readdir.c:108
 __do_sys_getdents fs/readdir.c:322 [inline]
 __se_sys_getdents+0x1ff/0x4e0 fs/readdir.c:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8e2198cda9
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:00007f8e22801038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f8e21ba5fa0 RCX: 00007f8e2198cda9
RDX: 0000000000000054 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f8e21a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8e21ba5fa0 R15: 00007ffe4d125dc8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xc2b pfn:0x5b4d7
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00016d3608 ffffea00016d3588 0000000000000000
raw: 0000000000000c2b 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 6170, tgid 6169 (syz.0.16), ts 124572467723, free_ts 124809275746
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x351d/0x36b0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 folio_alloc_mpol_noprof+0x36/0x70 mm/mempolicy.c:2320
 shmem_alloc_folio mm/shmem.c:1854 [inline]
 shmem_alloc_and_add_folio+0x490/0x1070 mm/shmem.c:1893
 shmem_get_folio_gfp+0x655/0x1800 mm/shmem.c:2533
 shmem_get_folio mm/shmem.c:2639 [inline]
 shmem_write_begin+0x17e/0x3a0 mm/shmem.c:3289
 generic_perform_write+0x329/0xa10 mm/filemap.c:4102
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3464
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0x70f/0xd10 fs/read_write.c:684
 ksys_write+0x19d/0x2d0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 6155 tgid 6155 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 free_unref_folios+0xdfd/0x17e0 mm/page_alloc.c:2737
 folios_put_refs+0x70a/0x800 mm/swap.c:992
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x595/0x1820 mm/shmem.c:1125
 shmem_truncate_range mm/shmem.c:1237 [inline]
 shmem_evict_inode+0x29d/0xa80 mm/shmem.c:1365
 evict+0x4f9/0x9b0 fs/inode.c:810
 __dentry_kill+0x20d/0x630 fs/dcache.c:660
 dput+0x19f/0x2b0 fs/dcache.c:902
 __fput+0x60b/0x9f0 fs/file_table.c:473
 task_work_run+0x251/0x310 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88805b4d7780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805b4d7800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805b4d7880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88805b4d7900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805b4d7980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================