EXT4-fs (loop4): mounted filesystem without journal. Opts: user_xattr,nombcache,noblock_validity,norecovery,debug_want_extra_isize=0x0000000000000080,lazytime,nodelalloc,usrquota,noauto_da_alloc,,errors=continue ================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xee/0x1b0 fs/ext4/namei.c:1504 Read of size 1 at addr ffff8881ebcdb6ef by task syz-executor.4/7542 CPU: 0 PID: 7542 Comm: syz-executor.4 Not tainted 5.4.268-syzkaller-00012-g51cf29fc2bfc #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+0x1d8/0x241 lib/dump_stack.c:118 print_address_description+0x8c/0x600 mm/kasan/report.c:384 __kasan_report+0xf3/0x120 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:653 ext4_search_dir+0xee/0x1b0 fs/ext4/namei.c:1504 ext4_find_inline_entry+0x4b6/0x5e0 fs/ext4/inline.c:1698 __ext4_find_entry+0x2a9/0x1b50 fs/ext4/namei.c:1577 ext4_lookup_entry fs/ext4/namei.c:1730 [inline] ext4_lookup+0x3c6/0xaa0 fs/ext4/namei.c:1798 __lookup_hash+0x117/0x240 fs/namei.c:1623 filename_create+0x202/0x750 fs/namei.c:3736 user_path_create fs/namei.c:3793 [inline] do_mkdirat+0xc5/0x2c0 fs/namei.c:3931 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Allocated by task 3668: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842 getname_flags+0xb8/0x4e0 fs/namei.c:141 getname fs/namei.c:212 [inline] __do_sys_unlink fs/namei.c:4211 [inline] __se_sys_unlink fs/namei.c:4209 [inline] __x64_sys_unlink+0x38/0x50 fs/namei.c:4209 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Freed by task 3668: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook mm/slub.c:1494 [inline] slab_free mm/slub.c:3080 [inline] kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096 putname fs/namei.c:262 [inline] do_unlinkat+0x7e8/0x8b0 fs/namei.c:4185 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 The buggy address belongs to the object at ffff8881ebcdb300 which belongs to the cache names_cache of size 4096 The buggy address is located 1007 bytes inside of 4096-byte region [ffff8881ebcdb300, ffff8881ebcdc300) The buggy address belongs to the page: page:ffffea0007af3600 refcount:1 mapcount:0 mapping:ffff8881f5d04000 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d04000 raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL) set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x18f/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4891 alloc_slab_page+0x39/0x3c0 mm/slub.c:343 allocate_slab mm/slub.c:1683 [inline] new_slab+0x97/0x440 mm/slub.c:1749 new_slab_objects mm/slub.c:2505 [inline] ___slab_alloc+0x2fe/0x490 mm/slub.c:2667 __slab_alloc+0x62/0xa0 mm/slub.c:2707 slab_alloc_node mm/slub.c:2792 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0x109/0x250 mm/slub.c:2842 getname_flags+0xb8/0x4e0 fs/namei.c:141 getname fs/namei.c:212 [inline] do_symlinkat+0xa1/0x400 fs/namei.c:4244 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1176 [inline] __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438 free_the_page mm/page_alloc.c:4953 [inline] __free_pages+0x91/0x140 mm/page_alloc.c:4959 __free_slab+0x221/0x2e0 mm/slub.c:1774 free_slab mm/slub.c:1789 [inline] discard_slab mm/slub.c:1795 [inline] unfreeze_partials+0x14e/0x180 mm/slub.c:2288 put_cpu_partial+0x44/0x180 mm/slub.c:2324 __slab_free+0x297/0x360 mm/slub.c:2971 qlist_free_all+0x43/0xb0 mm/kasan/quarantine.c:167 quarantine_reduce+0x1d9/0x210 mm/kasan/quarantine.c:260 __kasan_kmalloc+0x41/0x210 mm/kasan/common.c:507 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2829 [inline] slab_alloc mm/slub.c:2837 [inline] kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842 getname_flags+0xb8/0x4e0 fs/namei.c:141 do_sys_open+0x357/0x810 fs/open.c:1107 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 Memory state around the buggy address: ffff8881ebcdb580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ebcdb600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881ebcdb680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881ebcdb700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ebcdb780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== EXT4-fs error (device loop4): ext4_find_dest_de:2063: inode #12: block 7: comm syz-executor.4: bad entry in directory: directory entry overrun - offset=0, inode=2024452, rec_len=43608, size=56 fake=0