==================================================================
BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246
Read of size 1 at addr ffff888117141c67 by task syz-executor/467

CPU: 1 PID: 467 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x71/0x1e0 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:418
 kasan_report+0x122/0x150 mm/kasan/report.c:522
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:348
 ext4_htree_fill_tree+0x1066/0x10d0 fs/ext4/namei.c:1246
 ext4_dx_readdir fs/ext4/dir.c:608 [inline]
 ext4_readdir+0x2d8a/0x3c10 fs/ext4/dir.c:145
 iterate_dir+0x271/0x610 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
 x64_sys_call+0x15c/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f714b3bfad3
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:00007ffed4419628 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 000055555e9f94e0 RCX: 00007f714b3bfad3
RDX: 0000000000008000 RSI: 000055555e9f94e0 RDI: 0000000000000005
RBP: 000055555e9f94b4 R08: 0000000000028b61 R09: 0000000000000000
R10: 00007f714b57cca0 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 000055555e9f94b0 R15: 00007ffed441b8e0
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00045c5040 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x117141
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea000459c888 ffffea0004730a48 0000000000000000
raw: 0000000000000000 00000000000f0000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 204, tgid 204 (dhcpcd-run-hook), ts 15253148699, free_ts 54151281414
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554
 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1962 [inline]
 new_slab+0x98/0x3d0 mm/slub.c:2015
 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203
 __slab_alloc+0x5e/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+0x1b0/0x330 mm/slub.c:3447
 vm_area_dup+0x27/0x280 kernel/fork.c:511
 dup_mmap kernel/fork.c:724 [inline]
 dup_mm kernel/fork.c:1644 [inline]
 copy_mm+0xb45/0x1a10 kernel/fork.c:1696
 copy_process+0x12b4/0x3480 kernel/fork.c:2459
 kernel_clone+0x23a/0x810 kernel/fork.c:2874
 __do_sys_clone kernel/fork.c:3017 [inline]
 __se_sys_clone kernel/fork.c:3001 [inline]
 __x64_sys_clone+0x168/0x1b0 kernel/fork.c:3001
 x64_sys_call+0x990/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1551 [inline]
 free_pcp_prepare mm/page_alloc.c:1625 [inline]
 free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589
 free_unref_page+0x8f/0x530 mm/page_alloc.c:3687
 free_the_page mm/page_alloc.c:836 [inline]
 __free_pages+0x67/0x100 mm/page_alloc.c:5957
 __free_slab+0xca/0x1a0 mm/slub.c:2039
 free_slab mm/slub.c:2054 [inline]
 discard_slab mm/slub.c:2060 [inline]
 __unfreeze_partials+0x160/0x190 mm/slub.c:2609
 put_cpu_partial+0xa9/0x100 mm/slub.c:2685
 __slab_free+0x1c4/0x280 mm/slub.c:3563
 do_slab_free mm/slub.c:3640 [inline]
 ___cache_free+0xbf/0xd0 mm/slub.c:3696
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:310
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3421 [inline]
 kmem_cache_alloc_node+0x181/0x340 mm/slub.c:3468
 __alloc_skb+0xea/0x4b0 net/core/skbuff.c:508
 alloc_skb include/linux/skbuff.h:1290 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
 netlink_sendmsg+0x626/0xbc0 net/netlink/af_netlink.c:1848
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 __sys_sendto+0x464/0x5e0 net/socket.c:2143

Memory state around the buggy address:
 ffff888117141b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888117141b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888117141c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                       ^
 ffff888117141c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888117141d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs (loop5): unmounting filesystem.