EXT4-fs error (device loop0): make_indexed_dir:2284: inode #2: block 255: comm syz.0.20: 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.0.20: Unrecognised inode hash code 49 EXT4-fs warning (device loop0): dx_probe:965: inode #2: comm syz.0.20: 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 ffff8881260d0003 by task syz.0.20/481 CPU: 0 PID: 481 Comm: syz.0.20 Not tainted 5.15.151-syzkaller-1069524-gdb06c48ab67e #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 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: 0033:0x7f34d06c0b29 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:00007f34d014a048 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00007f34d084efa0 RCX: 00007f34d06c0b29 RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f34d0741756 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f34d084efa0 R15: 00007ffc63e7a3a8 The buggy address belongs to the page: page:ffffea0004983400 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x1260d0 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004983448 ffff8881f703c580 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 478, ts 45728803095, free_ts 45993266967 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1a3/0x1b0 mm/page_alloc.c:2604 prep_new_page+0x1b/0x110 mm/page_alloc.c:2610 get_page_from_freelist+0x3550/0x35d0 mm/page_alloc.c:4484 __alloc_pages+0x27e/0x8f0 mm/page_alloc.c:5776 __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] shmem_alloc_page mm/shmem.c:1587 [inline] shmem_alloc_and_acct_page+0x4bd/0xa80 mm/shmem.c:1612 shmem_getpage_gfp+0x1388/0x23c0 mm/shmem.c:1907 shmem_getpage mm/shmem.c:152 [inline] shmem_write_begin+0xca/0x1b0 mm/shmem.c:2478 generic_perform_write+0x2bc/0x5a0 mm/filemap.c:3849 __generic_file_write_iter+0x25b/0x4b0 mm/filemap.c:3976 generic_file_write_iter+0xaf/0x1c0 mm/filemap.c:4008 call_write_iter include/linux/fs.h:2204 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0xd5d/0x1110 fs/read_write.c:594 ksys_write+0x199/0x2c0 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:656 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 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1471 [inline] free_pcp_prepare mm/page_alloc.c:1543 [inline] free_unref_page_prepare+0x7c8/0x7d0 mm/page_alloc.c:3533 free_unref_page_list+0x14b/0xa60 mm/page_alloc.c:3670 release_pages+0x1310/0x1370 mm/swap.c:1009 __pagevec_release+0x84/0x100 mm/swap.c:1029 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x604/0x1560 mm/shmem.c:965 shmem_truncate_range mm/shmem.c:1064 [inline] shmem_evict_inode+0x215/0x9d0 mm/shmem.c:1146 evict+0x2a3/0x630 fs/inode.c:587 iput_final fs/inode.c:1705 [inline] iput+0x63b/0x7e0 fs/inode.c:1731 dentry_unlink_inode+0x34f/0x440 fs/dcache.c:376 __dentry_kill+0x447/0x660 fs/dcache.c:582 dentry_kill+0xc0/0x2a0 dput+0x45/0x80 fs/dcache.c:889 __fput+0x662/0x910 fs/file_table.c:288 ____fput+0x15/0x20 fs/file_table.c:308 task_work_run+0x129/0x190 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0xc4/0xe0 kernel/entry/common.c:175 Memory state around the buggy address: ffff8881260cff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881260cff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881260d0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8881260d0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8881260d0100: 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.0.20: path /root/syzkaller.rtIQ4V/5/file0: bad entry in directory: rec_len % 4 != 0 - offset=1023, inode=1797288960, rec_len=29285, size=1024 fake=0