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BUG: KASAN: slab-out-of-bounds in ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246
Read of size 1 at addr ffff88811a1f5a67 by task syz-executor/466

CPU: 0 PID: 466 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+0x21/0x30 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:427 [inline]
 kasan_report+0xf1/0x140 mm/kasan/report.c:444
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306
 ext4_htree_fill_tree+0x106b/0x10d0 fs/ext4/namei.c:1246
 ext4_dx_readdir fs/ext4/dir.c:609 [inline]
 ext4_readdir+0x2bfd/0x3a40 fs/ext4/dir.c:145
 iterate_dir+0x260/0x600 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+0x592/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7f80538693
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 82 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:00007ffdaec6f4d8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 000055557e51e4e0 RCX: 00007f7f80538693
RDX: 0000000000008000 RSI: 000055557e51e4e0 RDI: 0000000000000005
RBP: 000055557e51e4b4 R08: 0000000000028b61 R09: 0000000000000000
R10: 00007f7f806cbca0 R11: 0000000000000293 R12: ffffffffffffffa8
R13: 0000000000000010 R14: 000055557e51e4b0 R15: 0000000000000001
 </TASK>

Allocated by task 123:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:433 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466
 kasan_slab_alloc include/linux/kasan.h:217 [inline]
 slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550
 slab_alloc_node mm/slub.c:3245 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260
 vm_area_dup+0x26/0x210 kernel/fork.c:368
 dup_mmap kernel/fork.c:602 [inline]
 dup_mm kernel/fork.c:1522 [inline]
 copy_mm+0x93a/0x13a0 kernel/fork.c:1574
 copy_process+0x115c/0x3210 kernel/fork.c:2348
 kernel_clone+0x23f/0x940 kernel/fork.c:2737
 __do_sys_clone kernel/fork.c:2863 [inline]
 __se_sys_clone kernel/fork.c:2847 [inline]
 __x64_sys_clone+0x176/0x1d0 kernel/fork.c:2847
 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88811a1f5940
 which belongs to the cache vm_area_struct of size 232
The buggy address is located 63 bytes to the right of
 232-byte region [ffff88811a1f5940, ffff88811a1f5a28)
The buggy address belongs to the page:
page:ffffea0004687d40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11a1f5
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100186600
raw: 0000000000000000 00000000000d000d 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 123, ts 4997282611, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611
 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485
 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5808
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1937 [inline]
 new_slab+0xa1/0x4d0 mm/slub.c:2000
 ___slab_alloc+0x381/0x810 mm/slub.c:3033
 __slab_alloc+0x49/0x90 mm/slub.c:3120
 slab_alloc_node mm/slub.c:3211 [inline]
 slab_alloc mm/slub.c:3255 [inline]
 kmem_cache_alloc+0x138/0x260 mm/slub.c:3260
 vm_area_dup+0x26/0x210 kernel/fork.c:368
 dup_mmap kernel/fork.c:602 [inline]
 dup_mm kernel/fork.c:1522 [inline]
 copy_mm+0x93a/0x13a0 kernel/fork.c:1574
 copy_process+0x115c/0x3210 kernel/fork.c:2348
 kernel_clone+0x23f/0x940 kernel/fork.c:2737
 __do_sys_clone kernel/fork.c:2863 [inline]
 __se_sys_clone kernel/fork.c:2847 [inline]
 __x64_sys_clone+0x176/0x1d0 kernel/fork.c:2847
 x64_sys_call+0x41f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88811a1f5900: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88811a1f5980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88811a1f5a00: 00 00 00 00 00 fc fc fc fc fc fc fc fc 00 00 00
                                                       ^
 ffff88811a1f5a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88811a1f5b00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
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