==================================================================
BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1316/0x13e0 fs/ext4/namei.c:1246
Read of size 1 at addr ffff88811b9d8535 by task syz-executor/477

CPU: 0 PID: 477 Comm: syz-executor Not tainted 6.1.128-syzkaller-1167804-g9bcabbda673a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348
 ext4_htree_fill_tree+0x1316/0x13e0 fs/ext4/namei.c:1246
 ext4_dx_readdir fs/ext4/dir.c:605 [inline]
 ext4_readdir+0x2e6f/0x3860 fs/ext4/dir.c:142
 iterate_dir+0x265/0x600
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354
 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354
 x64_sys_call+0x5ae/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff8809bfad3
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 72 3e 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:00007ffcc5d01f28 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 0000555577d5e4e0 RCX: 00007ff8809bfad3
RDX: 0000000000008000 RSI: 0000555577d5e4e0 RDI: 0000000000000005
RBP: 0000555577d5e4b4 R08: 0000000000028b61 R09: 0000000000000000
R10: 00007ff880b7cca0 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 0000555577d5e4b0 R15: 00007ffcc5d041e0
 </TASK>

Allocated by task 136:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3421 [inline]
 slab_alloc mm/slub.c:3431 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3438 [inline]
 kmem_cache_alloc+0x175/0x320 mm/slub.c:3447
 vm_area_alloc+0x24/0x1b0 kernel/fork.c:495
 __mmap_region mm/mmap.c:2837 [inline]
 mmap_region+0xbfd/0x2c40 mm/mmap.c:3005
 do_mmap+0x853/0xe30 mm/mmap.c:1474
 vm_mmap_pgoff+0x208/0x430 mm/util.c:525
 ksys_mmap_pgoff+0x15d/0x1e0 mm/mmap.c:1520
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:93 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:86
 x64_sys_call+0x67/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:10
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 136:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1745 [inline]
 slab_free_freelist_hook mm/slub.c:1771 [inline]
 slab_free mm/slub.c:3686 [inline]
 kmem_cache_free+0x291/0x560 mm/slub.c:3711
 __vm_area_free+0x83/0x130 kernel/fork.c:536
 remove_vma mm/mmap.c:148 [inline]
 exit_mmap+0x549/0xbb0 mm/mmap.c:3369
 __mmput+0x95/0x310 kernel/fork.c:1299
 mmput+0x56/0x170 kernel/fork.c:1322
 exit_mm kernel/exit.c:568 [inline]
 do_exit+0xb24/0x2b80 kernel/exit.c:864
 do_group_exit+0x21a/0x2d0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
 x64_sys_call+0x610/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88811b9d8528
 which belongs to the cache vm_area_struct of size 200
The buggy address is located 13 bytes inside of
 200-byte region [ffff88811b9d8528, ffff88811b9d85f0)

The buggy address belongs to the physical page:
page:ffffea00046e7600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11b9d8
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881002a8780
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 136, tgid 136 (S41dhcpcd), ts 6336345840, free_ts 6334922444
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x213/0x220 mm/page_alloc.c:2637
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2644
 get_page_from_freelist+0x3a98/0x3b10 mm/page_alloc.c:4539
 __alloc_pages+0x234/0x610 mm/page_alloc.c:5837
 alloc_slab_page+0x6c/0xf0
 allocate_slab mm/slub.c:1962 [inline]
 new_slab+0x90/0x3e0 mm/slub.c:2015
 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203
 __slab_alloc+0x5d/0xa0 mm/slub.c:3302
 slab_alloc_node mm/slub.c:3387 [inline]
 slab_alloc mm/slub.c:3431 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3438 [inline]
 kmem_cache_alloc+0x1be/0x320 mm/slub.c:3447
 vm_area_dup+0x27/0x290 kernel/fork.c:510
 __split_vma+0x1bd/0x800 mm/mmap.c:2423
 do_mas_align_munmap+0x870/0x13a0 mm/mmap.c:2563
 do_mas_munmap+0x23e/0x2b0 mm/mmap.c:2726
 __mmap_region mm/mmap.c:2774 [inline]
 mmap_region+0x941/0x2c40 mm/mmap.c:3005
 do_mmap+0x853/0xe30 mm/mmap.c:1474
 vm_mmap_pgoff+0x208/0x430 mm/util.c:525
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1545 [inline]
 free_pcp_prepare mm/page_alloc.c:1619 [inline]
 free_unref_page_prepare+0x9f1/0xa00 mm/page_alloc.c:3581
 free_unref_page_list+0xf1/0x7b0 mm/page_alloc.c:3729
 release_pages+0xef9/0xf50 mm/swap.c:1043
 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:315
 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+0x1e0/0x3f0 mm/mmu_gather.c:361
 exit_mmap+0x45b/0xbb0 mm/mmap.c:3359
 __mmput+0x95/0x310 kernel/fork.c:1299
 mmput+0x56/0x170 kernel/fork.c:1322
 exec_mmap+0x417/0x4a0 fs/exec.c:1041
 begin_new_exec+0xa59/0x1ce0 fs/exec.c:1301
 load_elf_binary+0x95e/0x2680 fs/binfmt_elf.c:1002
 search_binary_handler fs/exec.c:1743 [inline]
 exec_binprm fs/exec.c:1784 [inline]
 bprm_execve+0x731/0x1480 fs/exec.c:1853
 do_execveat_common+0x90a/0xab0 fs/exec.c:1958
 do_execve fs/exec.c:2032 [inline]
 __do_sys_execve fs/exec.c:2108 [inline]
 __se_sys_execve fs/exec.c:2103 [inline]
 __x64_sys_execve+0x92/0xb0 fs/exec.c:2103
 x64_sys_call+0x1c5/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:60
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81

Memory state around the buggy address:
 ffff88811b9d8400: fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb
 ffff88811b9d8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
>ffff88811b9d8500: fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88811b9d8580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff88811b9d8600: fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb fb
==================================================================
EXT4-fs (loop2): unmounting filesystem.