loop2: detected capacity change from 0 to 512
EXT4-fs (loop2): 1 truncate cleaned up
EXT4-fs (loop2): mounted filesystem without journal. Quota mode: none.
EXT4-fs error (device loop2): ext4_validate_block_bitmap:438: comm syz.2.21: bg 0: block 465: padding at end of block bitmap is not set
EXT4-fs (loop2): Remounting filesystem read-only
==================================================================
BUG: KASAN: use-after-free in ext4_read_inline_data fs/ext4/inline.c:210 [inline]
BUG: KASAN: use-after-free in ext4_inlinedir_to_tree+0x503/0xfb0 fs/ext4/inline.c:1420
Read of size 52 at addr ffff888126692b97 by task syz.2.21/495

CPU: 0 PID: 495 Comm: syz.2.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 memcpy+0x2d/0x70 mm/kasan/shadow.c:65
 ext4_read_inline_data fs/ext4/inline.c:210 [inline]
 ext4_inlinedir_to_tree+0x503/0xfb0 fs/ext4/inline.c:1420
 ext4_htree_fill_tree+0x516/0x10e0 fs/ext4/namei.c:1211
 ext4_dx_readdir fs/ext4/dir.c:608 [inline]
 ext4_readdir+0x2d9f/0x3c10 fs/ext4/dir.c:145
 iterate_dir+0x26d/0x610 fs/readdir.c:-1
 __do_sys_getdents fs/readdir.c:286 [inline]
 __se_sys_getdents+0xf2/0x250 fs/readdir.c:271
 __x64_sys_getdents+0x7b/0x90 fs/readdir.c:271
 x64_sys_call+0x212/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:79
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4f83d9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4f84bce028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f4f84015fa0 RCX: 00007f4f83d9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f4f83e32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f84016038 R14: 00007f4f84015fa0 R15: 00007ffe454ed2a8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000499a480 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x126692
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea000499d588 ffffea000499d4c8 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 419, tgid 419 (udevd), ts 41333138768, free_ts 41333572086
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680
 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587
 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931
 __folio_alloc+0x12/0x40 mm/page_alloc.c:5964
 __folio_alloc_node include/linux/gfp.h:245 [inline]
 folio_alloc include/linux/gfp.h:274 [inline]
 shmem_alloc_folio mm/shmem.c:1597 [inline]
 shmem_alloc_and_acct_folio+0x6dd/0x8c0 mm/shmem.c:1622
 shmem_get_folio_gfp+0xd6d/0x20f0 mm/shmem.c:1951
 shmem_get_folio mm/shmem.c:2082 [inline]
 shmem_write_begin+0xea/0x2c0 mm/shmem.c:2567
 generic_perform_write+0x32d/0x740 mm/filemap.c:3927
 __generic_file_write_iter+0x17a/0x230 mm/filemap.c:4026
 generic_file_write_iter+0xae/0x310 mm/filemap.c:4055
 call_write_iter include/linux/fs.h:2282 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x5ef/0xd00 fs/read_write.c:584
 ksys_write+0x14a/0x260 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1581 [inline]
 free_pcp_prepare mm/page_alloc.c:1655 [inline]
 free_unref_page_prepare+0x81b/0x820 mm/page_alloc.c:3622
 free_unref_page_list+0x117/0x8d0 mm/page_alloc.c:3773
 release_pages+0xc7e/0xce0 mm/swap.c:1053
 __pagevec_release+0x71/0xe0 mm/swap.c:1073
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x564/0x14e0 mm/shmem.c:951
 shmem_truncate_range mm/shmem.c:1067 [inline]
 shmem_evict_inode+0x21f/0x9c0 mm/shmem.c:1176
 evict+0x4c4/0x8c0 fs/inode.c:709
 iput_final fs/inode.c:1845 [inline]
 iput+0x633/0x690 fs/inode.c:1871
 dentry_unlink_inode+0x346/0x3f0 fs/dcache.c:405
 __dentry_kill+0x46c/0x680 fs/dcache.c:611
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:918
 do_renameat2+0xa33/0xfc0 fs/namei.c:5036
 __do_sys_rename fs/namei.c:5080 [inline]
 __se_sys_rename fs/namei.c:5078 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:5078
 x64_sys_call+0x300/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76

Memory state around the buggy address:
 ffff888126692a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888126692b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888126692b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                         ^
 ffff888126692c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888126692c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop2): ext4_inlinedir_to_tree:1458: inode #12: block 7: comm syz.2.21: path /4/file1/file0: bad entry in directory: rec_len % 4 != 0 - offset=35110, inode=3517778242, rec_len=35106, size=112 fake=0
EXT4-fs (loop2): Remounting filesystem read-only