EXT4-fs (loop1): mounted filesystem without journal. Opts: errors=remount-ro,
EXT4-fs error (device loop1): ext4_validate_block_bitmap:438: comm syz.1.549: bg 0: block 465: padding at end of block bitmap is not set
EXT4-fs (loop1): Remounting filesystem read-only
==================================================================
BUG: KASAN: use-after-free in ext4_read_inline_data fs/ext4/inline.c:209 [inline]
BUG: KASAN: use-after-free in ext4_inlinedir_to_tree+0x5f6/0xfd0 fs/ext4/inline.c:1419
Read of size 52 at addr ffff88813b47205f by task syz.1.549/2456

CPU: 1 PID: 2456 Comm: syz.1.549 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 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:209 [inline]
 ext4_inlinedir_to_tree+0x5f6/0xfd0 fs/ext4/inline.c:1419
 ext4_htree_fill_tree+0x508/0x1160 fs/ext4/namei.c:1186
 ext4_dx_readdir fs/ext4/dir.c:601 [inline]
 ext4_readdir+0x2c49/0x3ab0 fs/ext4/dir.c:145
 iterate_dir+0x260/0x570 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
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f5759c43cb9
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:00007f57586a0028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f5759ebefa0 RCX: 00007f5759c43cb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000a
RBP: 00007f5759cb1bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5759ebf038 R14: 00007f5759ebefa0 R15: 00007ffc1f5b7758

The buggy address belongs to the page:
page:ffffea0004ed1c80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x13b472
flags: 0x4000000000000000()
raw: 4000000000000000 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 2338, ts 109114384562, free_ts 109733578752
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5370
 __alloc_pages include/linux/gfp.h:544 [inline]
 __alloc_pages_node include/linux/gfp.h:557 [inline]
 alloc_pages_node include/linux/gfp.h:571 [inline]
 alloc_pages include/linux/gfp.h:590 [inline]
 shmem_alloc_page+0x1fd/0x380 mm/shmem.c:1584
 shmem_alloc_and_acct_page+0x3b7/0x820 mm/shmem.c:1609
 shmem_getpage_gfp+0x625/0x2120 mm/shmem.c:1922
 shmem_fault+0x2b5/0x650 mm/shmem.c:2143
 __do_fault mm/memory.c:4064 [inline]
 do_read_fault mm/memory.c:4399 [inline]
 do_fault mm/memory.c:4527 [inline]
 handle_pte_fault+0x1fa5/0x3750 mm/memory.c:4791
 __handle_mm_fault mm/memory.c:4944 [inline]
 handle_mm_fault+0xf81/0x1710 mm/memory.c:5358
 faultin_page mm/gup.c:902 [inline]
 __get_user_pages+0xbf8/0x1400 mm/gup.c:1121
 populate_vma_page_range mm/gup.c:1454 [inline]
 __mm_populate+0x34f/0x440 mm/gup.c:1502
 mm_populate include/linux/mm.h:2793 [inline]
 vm_mmap_pgoff+0x254/0x370 mm/util.c:548
 ksys_mmap_pgoff+0xfd/0x1e0 mm/mmap.c:1712
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x129/0x9c0 mm/page_alloc.c:3443
 release_pages+0xe52/0xea0 mm/swap.c:1103
 __pagevec_release+0x71/0xe0 mm/swap.c:1123
 pagevec_release include/linux/pagevec.h:88 [inline]
 shmem_undo_range+0x74a/0x1810 mm/shmem.c:969
 shmem_truncate_range mm/shmem.c:1073 [inline]
 shmem_evict_inode+0x210/0xa00 mm/shmem.c:1173
 evict+0x4ae/0x930 fs/inode.c:612
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 dentry_unlink_inode+0x2cf/0x380 fs/dcache.c:378
 __dentry_kill+0x44f/0x650 fs/dcache.c:583
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:883
 __fput+0x4fe/0x770 fs/file_table.c:294
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x127/0x190 kernel/task_work.c:189
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0xa90/0x2500 kernel/exit.c:872

Memory state around the buggy address:
 ffff88813b471f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88813b471f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88813b472000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                    ^
 ffff88813b472080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88813b472100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop1): ext4_inlinedir_to_tree:1457: inode #12: block 7: comm syz.1.549: path /106/file1/file0: bad entry in directory: rec_len % 4 != 0 - offset=39503, inode=3885038053, rec_len=39499, size=112 fake=0