EXT4-fs warning (device loop0): dx_probe:845: inode #2: comm syz-executor966: Hash code is SIPHASH, but hash not in dirent
EXT4-fs warning (device loop0): dx_probe:966: inode #2: comm syz-executor966: Corrupt directory, running e2fsck is recommended
==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85
Read of size 2 at addr ffff888122c89003 by task syz-executor966/296
CPU: 0 PID: 296 Comm: syz-executor966 Not tainted 5.15.185-syzkaller-00339-ge678c93d43cc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:307
__ext4_check_dir_entry+0x7c2/0x970 fs/ext4/dir.c:85
ext4_readdir+0x11c9/0x3a40 fs/ext4/dir.c:261
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: 0033:0x7fdf3ea8e329
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff6616edd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fdf3ead70e0 RCX: 00007fdf3ea8e329
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007fdf3ead70a0 R08: 00007fff6616ee10 R09: 00007fff6616ee10
R10: 00007fff6616ee10 R11: 0000000000000246 R12: 00007fff6616edfc
R13: 0000000000000001 R14: 431bde82d7b634db R15: 00007fff6616ee30
</TASK>
The buggy address belongs to the page:
page:ffffea00048b2240 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x122c89
flags: 0x4000000000000000(zone=1)
raw: 4000000000000000 ffffea00048b2288 ffffea00048a6988 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 272, ts 20030323624, free_ts 20040695402
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:5789
__alloc_pages_node include/linux/gfp.h:591 [inline]
alloc_pages_node include/linux/gfp.h:605 [inline]
alloc_pages include/linux/gfp.h:618 [inline]
do_anonymous_page mm/memory.c:4068 [inline]
handle_pte_fault+0xe89/0x2680 mm/memory.c:4908
__handle_mm_fault mm/memory.c:-1 [inline]
do_handle_mm_fault+0x1a6d/0x1d50 mm/memory.c:5332
handle_mm_fault include/linux/mm.h:1836 [inline]
do_user_addr_fault+0x841/0x1180 arch/x86/mm/fault.c:1418
handle_page_fault arch/x86/mm/fault.c:1509 [inline]
exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1565
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606
page last free stack trace:
reset_page_owner include/linux/page_owner.h:26 [inline]
free_pages_prepare mm/page_alloc.c:1472 [inline]
free_pcp_prepare mm/page_alloc.c:1544 [inline]
free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534
free_unref_page_list+0x134/0x9d0 mm/page_alloc.c:3671
release_pages+0x1076/0x10d0 mm/swap.c:1009
free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:320
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+0x175/0x300 mm/mmu_gather.c:338
unmap_region+0x315/0x360 mm/mmap.c:2680
__do_munmap+0xa0e/0xfe0 mm/mmap.c:2913
__vm_munmap+0x15b/0x2a0 mm/mmap.c:2966
__do_sys_munmap mm/mmap.c:2992 [inline]
__se_sys_munmap mm/mmap.c:2988 [inline]
__x64_sys_munmap+0x6b/0x80 mm/mmap.c:2988
x64_sys_call+0xc9/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12
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:
ffff888122c88f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888122c88f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888122c89000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff888122c89080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888122c89100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop0): ext4_readdir:263: inode #2: block 255: comm syz-executor966: path (unknown): bad entry in directory: rec_len is smaller than minimal - offset=1023, inode=0, rec_len=0, size=1024 fake=0