==================================================================
BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221
Read of size 1 at addr ffff888121a3ed1b by task syz-executor/458

CPU: 1 PID: 458 Comm: syz-executor Not tainted 5.10.236-syzkaller-1007372-gab07aeb2c93d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 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
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1221
 ext4_dx_readdir fs/ext4/dir.c:601 [inline]
 ext4_readdir+0x2b45/0x39b0 fs/ext4/dir.c:145
 iterate_dir+0x260/0x570 fs/readdir.c:-1
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0xe5/0x240 fs/readdir.c:354
 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f70422398b3
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 62 43 f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8
RSP: 002b:00007ffdb0a926a8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00005555696364e0 RCX: 00007f70422398b3
RDX: 0000000000008000 RSI: 00005555696364e0 RDI: 0000000000000005
RBP: 00005555696364b4 R08: 0000000000028b61 R09: 0000000000000000
R10: 00007f7042395ca0 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 00005555696364b0 R15: 00007ffdb0a94950

The buggy address belongs to the page:
page:ffffea0004868f80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x121a3e
flags: 0x4000000000000000()
raw: 4000000000000000 ffffea0004868fc8 ffffea0004868f48 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 434, ts 62039890871, free_ts 62625113895
 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+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5349
 __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]
 do_cow_fault mm/memory.c:4418 [inline]
 do_fault mm/memory.c:4529 [inline]
 handle_pte_fault+0xf53/0x3750 mm/memory.c:4791
 __handle_mm_fault mm/memory.c:4944 [inline]
 handle_mm_fault+0xf3f/0x16a0 mm/memory.c:5358
 do_user_addr_fault+0x5a2/0xc80 arch/x86/mm/fault.c:1362
 handle_page_fault arch/x86/mm/fault.c:1428 [inline]
 exc_page_fault+0x5a/0xc0 arch/x86/mm/fault.c:1484
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571
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+0x12e/0x9b0 mm/page_alloc.c:3443
 release_pages+0xe38/0xe80 mm/swap.c:1103
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:356
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x175/0x300 mm/mmu_gather.c:326
 exit_mmap+0x2fc/0x540 mm/mmap.c:3375
 __mmput+0x93/0x2f0 kernel/fork.c:1153
 mmput+0x4e/0x150 kernel/fork.c:1176
 exit_mm kernel/exit.c:539 [inline]
 do_exit+0x986/0x2470 kernel/exit.c:850
 do_group_exit+0x141/0x310 kernel/exit.c:985
 get_signal+0xf7d/0x12e0 kernel/signal.c:2793
 arch_do_signal_or_restart+0xbf/0x10f0 arch/x86/kernel/signal.c:805
 handle_signal_work kernel/entry/common.c:145 [inline]
 exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0x68/0x90 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff888121a3ec00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888121a3ec80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888121a3ed00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                            ^
 ffff888121a3ed80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888121a3ee00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop0): __ext4_get_inode_loc:4437: comm syz-executor: Invalid inode table block 14875662660405297151 in block_group 0
EXT4-fs error (device loop0) in ext4_reserve_inode_write:5900: Corrupt filesystem
EXT4-fs error (device loop0): ext4_dirty_inode:6110: inode #2: comm syz-executor: mark_inode_dirty error