EXT4-fs warning (device loop3): dx_probe:893: inode #2: comm syz-executor.3: dx entry: limit 0 != root limit 124
EXT4-fs warning (device loop3): dx_probe:966: inode #2: comm syz-executor.3: Corrupt directory, running e2fsck is recommended
==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x738/0x8e0 fs/ext4/dir.c:85
Read of size 2 at addr ffff888074c33003 by task syz-executor.3/5469

CPU: 1 PID: 5469 Comm: syz-executor.3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 __ext4_check_dir_entry+0x738/0x8e0 fs/ext4/dir.c:85
 ext4_readdir+0x11df/0x3a60 fs/ext4/dir.c:261
 iterate_dir+0x218/0x560 fs/readdir.c:-1
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0xe5/0x260 fs/readdir.c:354
 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: 0033:0x7f9ffa293ee9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9ff96150c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f9ffa3cafa0 RCX: 00007f9ffa293ee9
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f9ffa2e047f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f9ffa3cafa0 R15: 00007ffd36e1c548
 </TASK>

Allocated by task 5205:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3238
 vm_area_dup+0x1e/0xb0 kernel/fork.c:358
 __split_vma+0xb1/0x410 mm/mmap.c:2730
 mprotect_fixup+0x5af/0x800 mm/mprotect.c:483
 do_mprotect_pkey+0x657/0x910 mm/mprotect.c:636
 __do_sys_mprotect mm/mprotect.c:662 [inline]
 __se_sys_mprotect mm/mprotect.c:659 [inline]
 __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:659
 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

Freed by task 5205:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3520
 remove_vma mm/mmap.c:188 [inline]
 exit_mmap+0x4d8/0x5f0 mm/mmap.c:3227
 __mmput+0x115/0x3b0 kernel/fork.c:1127
 exit_mm+0x567/0x6c0 kernel/exit.c:550
 do_exit+0x5a1/0x20a0 kernel/exit.c:870
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 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 ffff888074c33000
 which belongs to the cache vm_area_struct of size 200
The buggy address is located 3 bytes inside of
 200-byte region [ffff888074c33000, ffff888074c330c8)
The buggy address belongs to the page:
page:ffffea0001d30cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x74c33
memcg:ffff888074c62801
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888140007a00
raw: 0000000000000000 00000000000f000f 00000001ffffffff ffff888074c62801
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5205, ts 92400707228, free_ts 92390275651
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3238
 vm_area_dup+0x1e/0xb0 kernel/fork.c:358
 __split_vma+0xb1/0x410 mm/mmap.c:2730
 mprotect_fixup+0x5af/0x800 mm/mprotect.c:483
 do_mprotect_pkey+0x657/0x910 mm/mprotect.c:636
 __do_sys_mprotect mm/mprotect.c:662 [inline]
 __se_sys_mprotect mm/mprotect.c:659 [inline]
 __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:659
 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 last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x122/0x7e0 mm/page_alloc.c:3433
 release_pages+0x184b/0x1bb0 mm/swap.c:963
 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+0x164/0x2e0 mm/mmu_gather.c:338
 exit_mmap+0x3a6/0x5f0 mm/mmap.c:3218
 __mmput+0x115/0x3b0 kernel/fork.c:1127
 exec_mmap+0x4d1/0x5c0 fs/exec.c:1035
 begin_new_exec+0x7e8/0x1160 fs/exec.c:1293
 load_elf_binary+0x98e/0x2890 fs/binfmt_elf.c:1001
 search_binary_handler fs/exec.c:1742 [inline]
 exec_binprm fs/exec.c:1783 [inline]
 bprm_execve+0xa92/0x17d0 fs/exec.c:1852
 do_execveat_common+0x51e/0x6d0 fs/exec.c:1957
 do_execve fs/exec.c:2027 [inline]
 __do_sys_execve fs/exec.c:2103 [inline]
 __se_sys_execve fs/exec.c:2098 [inline]
 __x64_sys_execve+0x8e/0xa0 fs/exec.c:2098
 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

Memory state around the buggy address:
 ffff888074c32f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888074c32f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888074c33000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888074c33080: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
 ffff888074c33100: fc fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================