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BUG: KASAN: use-after-free in ext4_htree_fill_tree+0x10f0/0x1160 fs/ext4/namei.c:1221
Read of size 1 at addr ffff888119ea0535 by task syz-executor/499

CPU: 1 PID: 499 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_htree_fill_tree+0x10f0/0x1160 fs/ext4/namei.c:1221
 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_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0xf2/0x250 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: 0033:0x7fdae42159f3
Code: c7 c0 e8 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb 9e e8 81 9b fd ff 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 e8 ff ff ff f7 d8
RSP: 002b:00007ffdccd02848 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00005555707cf920 RCX: 00007fdae42159f3
RDX: 0000000000008000 RSI: 00005555707cf950 RDI: 0000000000000005
RBP: 00005555707cf950 R08: 00000000000286f1 R09: 0000000000000001
R10: 00007fdae438aca0 R11: 0000000000000293 R12: 00005555707cf924
R13: ffffffffffffffe8 R14: 0000000000000010 R15: 00007ffdccd04ae0

The buggy address belongs to the page:
page:ffffea000467a800 refcount:0 mapcount:-128 mapping:0000000000000000 index:0xffff888119ea5500 pfn:0x119ea0
flags: 0x4000000000000000()
raw: 4000000000000000 ffffea0004674808 ffffea0004682808 0000000000000000
raw: ffff888119ea5500 0000000000000005 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 120, ts 6533371378, free_ts 50116636639
 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:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc+0x1ac/0x2d0 mm/slub.c:2965
 getname_flags+0xb9/0x500 fs/namei.c:141
 getname+0x19/0x20 fs/namei.c:212
 do_sys_openat2+0xde/0x750 fs/open.c:1213
 do_sys_open fs/open.c:1235 [inline]
 __do_sys_openat fs/open.c:1251 [inline]
 __se_sys_openat fs/open.c:1246 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1246
 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_pages_ok+0x80b/0x830 mm/page_alloc.c:1629
 free_the_page mm/page_alloc.c:5445 [inline]
 __free_pages+0xd8/0x3b0 mm/page_alloc.c:5454
 __free_slab+0xcf/0x190 mm/slub.c:1899
 free_slab mm/slub.c:1914 [inline]
 discard_slab mm/slub.c:1920 [inline]
 unfreeze_partials+0x15f/0x190 mm/slub.c:2415
 put_cpu_partial+0xc1/0x180 mm/slub.c:2451
 __slab_free+0x2c9/0x3a0 mm/slub.c:3100
 do_slab_free mm/slub.c:3196 [inline]
 ___cache_free+0x10e/0x130 mm/slub.c:3215
 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580
 slab_alloc_node mm/slub.c:2952 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc_trace+0x15d/0x2e0 mm/slub.c:2977
 kmalloc include/linux/slab.h:555 [inline]
 syslog_print+0x133/0x750 kernel/printk/printk.c:1487
 do_syslog+0x94c/0x9a0 kernel/printk/printk.c:1644
 __do_sys_syslog kernel/printk/printk.c:1736 [inline]
 __se_sys_syslog kernel/printk/printk.c:1734 [inline]
 __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1734

Memory state around the buggy address:
 ffff888119ea0400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888119ea0480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888119ea0500: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                     ^
 ffff888119ea0580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888119ea0600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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