EXT4-fs error (device loop0): make_indexed_dir:2284: inode #2: block 255: comm syz.0.23: 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:832: inode #2: comm syz.0.23: Unrecognised inode hash code 49 EXT4-fs warning (device loop0): dx_probe:965: inode #2: comm syz.0.23: 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 ffff888120b16003 by task syz.0.23/487 CPU: 0 PID: 487 Comm: syz.0.23 Not tainted 5.15.152-syzkaller-1069667-g70e1a731d986 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description+0x87/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x179/0x1c0 mm/kasan/report.c:444 __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+0x1490/0x38d0 fs/ext4/dir.c:258 iterate_dir+0x265/0x610 __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_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc6b0b0bb29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc6b0595048 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007fc6b0c99fa0 RCX: 00007fc6b0b0bb29 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fc6b0b8c756 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc6b0c99fa0 R15: 00007ffdf6299fd8 The buggy address belongs to the page: page:ffffea000482c580 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x120b16 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea000491d448 ffffea000491d408 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 425, ts 42115849808, free_ts 42149167491 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1b/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4485 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5777 __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_cow_fault mm/memory.c:4540 [inline] do_fault mm/memory.c:4658 [inline] handle_pte_fault+0xa0c/0x24d0 mm/memory.c:4871 do_handle_mm_fault+0x20bc/0x2400 mm/memory.c:5293 handle_mm_fault include/linux/mm.h:1836 [inline] do_user_addr_fault arch/x86/mm/fault.c:1458 [inline] handle_page_fault arch/x86/mm/fault.c:1549 [inline] exc_page_fault+0x3b5/0x830 arch/x86/mm/fault.c:1605 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:568 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+0x7c8/0x7d0 mm/page_alloc.c:3534 free_unref_page_list+0x14b/0xa60 mm/page_alloc.c:3671 release_pages+0x1310/0x1370 mm/swap.c:1009 free_pages_and_swap_cache+0x8a/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+0x177/0x320 mm/mmu_gather.c:338 exit_mmap+0x40d/0x940 mm/mmap.c:3218 __mmput+0x95/0x310 kernel/fork.c:1179 mmput+0x5b/0x170 kernel/fork.c:1202 exit_mm kernel/exit.c:552 [inline] do_exit+0xb9c/0x2ca0 kernel/exit.c:865 do_group_exit+0x141/0x310 kernel/exit.c:1000 __do_sys_exit_group kernel/exit.c:1011 [inline] __se_sys_exit_group kernel/exit.c:1009 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1009 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff888120b15f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888120b15f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888120b16000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888120b16080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888120b16100: 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.0.23: path /root/syzkaller.rTpsjG/8/file0: bad entry in directory: rec_len is smaller than minimal - offset=1023, inode=0, rec_len=0, size=1024 fake=0