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.2.17: 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+0x50c/0xff0 fs/ext4/inline.c:1412
Read of size 52 at addr ffff88812fea705f by task syz.2.17/374

CPU: 1 PID: 374 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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+0x50c/0xff0 fs/ext4/inline.c:1412
 ext4_htree_fill_tree+0x508/0x1160 fs/ext4/namei.c:1211
 ext4_dx_readdir fs/ext4/dir.c:608 [inline]
 ext4_readdir+0x2f80/0x3e10 fs/ext4/dir.c:145
 iterate_dir+0x271/0x610 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: 0033:0x7f6ef599ce59
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:00007ffdea427278 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f6ef5c15fa0 RCX: 00007f6ef599ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f6ef5a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6ef5c15fac R14: 00007f6ef5c15fa0 R15: 00007f6ef5c15fa0
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0004bfa9c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x12fea7
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea0004bfdcc8 ffffea0004bfa988 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 0x8140dca(GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_ZERO|__GFP_CMA), pid 374, tgid 374 (syz.2.17), ts 31145958748, free_ts 31149334594
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679
 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4585
 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5929
 __folio_alloc+0x12/0x40 mm/page_alloc.c:5962
 __folio_alloc_node include/linux/gfp.h:245 [inline]
 folio_alloc include/linux/gfp.h:274 [inline]
 alloc_page_vma include/linux/gfp.h:283 [inline]
 do_anonymous_page mm/memory.c:4286 [inline]
 handle_pte_fault mm/memory.c:5181 [inline]
 __handle_mm_fault mm/memory.c:5325 [inline]
 handle_mm_fault+0x1972/0x26c0 mm/memory.c:5465
 do_user_addr_fault+0x905/0x1050 arch/x86/mm/fault.c:1321
 handle_page_fault arch/x86/mm/fault.c:1464 [inline]
 exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1517
 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1580 [inline]
 free_pcp_prepare mm/page_alloc.c:1654 [inline]
 free_unref_page_prepare+0x7f8/0x800 mm/page_alloc.c:3620
 free_unref_page_list+0x117/0x8c0 mm/page_alloc.c:3771
 release_pages+0xc93/0xcf0 mm/swap.c:1053
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:316
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu mm/mmu_gather.c:261 [inline]
 tlb_finish_mmu+0x1aa/0x370 mm/mmu_gather.c:361
 unmap_region+0x2b7/0x320 mm/mmap.c:2419
 do_mas_align_munmap+0xbed/0x1320 mm/mmap.c:2693
 do_mas_munmap+0x241/0x2b0 mm/mmap.c:2751
 __vm_munmap+0x1bd/0x330 mm/mmap.c:3050
 __do_sys_munmap mm/mmap.c:3076 [inline]
 __se_sys_munmap mm/mmap.c:3072 [inline]
 __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3072
 x64_sys_call+0x8a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12
 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

Memory state around the buggy address:
 ffff88812fea6f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812fea6f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88812fea7000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                    ^
 ffff88812fea7080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88812fea7100: 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:1450: inode #12: block 7: comm syz.2.17: path /0/file1/file0: bad entry in directory: rec_len % 4 != 0 - offset=39503, inode=3885038053, rec_len=39499, size=112 fake=0
EXT4-fs (loop2): Remounting filesystem read-only