EXT4-fs error (device loop0): make_indexed_dir:2245: inode #2: block 255: comm syz-executor320: bad entry in directory: rec_len is smaller than minimal - offset=1024, inode=5120, rec_len=0, size=993 fake=0 EXT4-fs warning (device loop0): dx_probe:805: inode #2: comm syz-executor320: Unrecognised inode hash code 49 EXT4-fs warning (device loop0): dx_probe:945: inode #2: comm syz-executor320: Corrupt directory, running e2fsck is recommended ================================================================== BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x700/0x880 fs/ext4/dir.c:85 Read of size 2 at addr ffff888116f28003 by task syz-executor320/321 CPU: 0 PID: 321 Comm: syz-executor320 Not tainted 5.10.210-syzkaller-00394-g70b6ab09a34b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118 print_address_description+0x81/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:452 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report_generic.c:307 __ext4_check_dir_entry+0x700/0x880 fs/ext4/dir.c:85 ext4_readdir+0x1402/0x37c0 fs/ext4/dir.c:258 iterate_dir+0x265/0x580 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0x1c1/0x460 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xc6 RIP: 0033:0x7fe88ee8e0e9 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:00007ffc23661ba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe88ee8e0e9 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00007ffc23661bdc R09: 00007ffc23661bdc R10: 00007ffc23661bdc R11: 0000000000000246 R12: 00007ffc23661bdc R13: 000000000000000a R14: 431bde82d7b634db R15: 00007ffc23661c10 The buggy address belongs to the page: page:ffffea00045bca00 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x1 pfn:0x116f28 flags: 0x4000000000000000() raw: 4000000000000000 ffffea00045bd6c8 ffffea0004431488 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffff7f 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 0x8100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO|0x8000000), pid 230, ts 14510620823, free_ts 14512075758 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x166/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5346 __alloc_pages include/linux/gfp.h:544 [inline] __alloc_pages_node include/linux/gfp.h:557 [inline] alloc_pages_node include/linux/gfp.h:571 [inline] alloc_pages include/linux/gfp.h:590 [inline] do_anonymous_page mm/memory.c:3934 [inline] handle_pte_fault+0x174f/0x3de0 mm/memory.c:4757 __handle_mm_fault mm/memory.c:4915 [inline] handle_mm_fault+0x11d6/0x1a10 mm/memory.c:5329 do_user_addr_fault arch/x86/mm/fault.c:1396 [inline] handle_page_fault arch/x86/mm/fault.c:1462 [inline] exc_page_fault+0x2a6/0x5b0 arch/x86/mm/fault.c:1518 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571 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_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336 free_unref_page_list+0x122/0xb20 mm/page_alloc.c:3443 release_pages+0xea0/0xef0 mm/swap.c:1103 free_pages_and_swap_cache+0x8a/0xa0 mm/swap_state.c:356 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+0x177/0x320 mm/mmu_gather.c:326 unmap_region+0x31c/0x370 mm/mmap.c:2807 __do_munmap+0x699/0x8c0 mm/mmap.c:3036 __vm_munmap mm/mmap.c:3059 [inline] __do_sys_munmap mm/mmap.c:3085 [inline] __se_sys_munmap+0x120/0x1a0 mm/mmap.c:3081 __x64_sys_munmap+0x5b/0x70 mm/mmap.c:3081 do_syscall_64+0x34/0x70 entry_SYSCALL_64_after_hwframe+0x61/0xc6 Memory state around the buggy address: ffff888116f27f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888116f27f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888116f28000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888116f28080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888116f28100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop0): ext4_readdir:260: inode #2: block 255: comm syz-executor320: path /root/syzkaller.u2Naqf/10/file0: bad entry in directory: rec_len is smaller than minimal - offset=1023, inode=0, rec_len=0, size=1024 fake=0