================================================================== BUG: KASAN: use-after-free in dx_insert_block+0xd9/0x240 fs/ext4/namei.c:1387 Read of size 157024 at addr ffff888134ae6028 by task syz.1.169/942 CPU: 1 PID: 942 Comm: syz.1.169 Not tainted 6.1.141-syzkaller-1169946-g145c7fad733f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x210 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:427 kasan_report+0x122/0x150 mm/kasan/report.c:531 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 mm/kasan/generic.c:189 memmove+0x2d/0x70 mm/kasan/shadow.c:54 dx_insert_block+0xd9/0x240 fs/ext4/namei.c:1387 do_split+0x19f0/0x1d90 fs/ext4/namei.c:2080 make_indexed_dir+0xe06/0x14a0 fs/ext4/namei.c:2392 ext4_add_entry+0xb45/0xd70 fs/ext4/namei.c:2504 __ext4_link+0x4d7/0x770 fs/ext4/namei.c:3522 ext4_link+0x1de/0x270 fs/ext4/namei.c:3563 vfs_link+0x64b/0x800 fs/namei.c:4598 do_linkat+0x1e7/0x730 fs/namei.c:4669 __do_sys_link fs/namei.c:4703 [inline] __se_sys_link fs/namei.c:4701 [inline] __x64_sys_link+0x86/0x90 fs/namei.c:4701 x64_sys_call+0x266/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:87 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fab3898cde9 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:00007fab39752038 EFLAGS: 00000246 ORIG_RAX: 0000000000000056 RAX: ffffffffffffffda RBX: 00007fab38ba5fa0 RCX: 00007fab3898cde9 RDX: 0000000000000000 RSI: 0000400000000bc0 RDI: 0000400000001240 RBP: 00007fab38a0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fab38ba5fa0 R15: 00007ffe08915988 The buggy address belongs to the physical page: page:ffffea0004d2b980 refcount:3 mapcount:1 mapping:ffff888111c02b50 index:0x1 pfn:0x134ae6 memcg:ffff88810f478000 aops:def_blk_aops ino:700001 flags: 0x460000000032205e(referenced|uptodate|dirty|lru|workingset|private|mappedtodisk|unevictable|mlocked|zone=1) raw: 460000000032205e dead000000000100 dead000000000001 ffff888111c02b50 raw: 0000000000000001 ffff888118b8ce70 0000000300000000 ffff88810f478000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 942, tgid 941 (syz.1.169), ts 105107295425, free_ts 105066113245 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2637 prep_new_page+0x1c/0x110 mm/page_alloc.c:2644 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4539 __alloc_pages+0x19e/0x3a0 mm/page_alloc.c:5850 __folio_alloc+0x12/0x40 mm/page_alloc.c:5882 __folio_alloc_node include/linux/gfp.h:245 [inline] folio_alloc include/linux/gfp.h:274 [inline] filemap_alloc_folio include/linux/pagemap.h:513 [inline] __filemap_get_folio+0x6ec/0x980 mm/filemap.c:2018 pagecache_get_page+0x2b/0x110 mm/folio-compat.c:110 find_or_create_page include/linux/pagemap.h:654 [inline] grow_dev_page fs/buffer.c:989 [inline] grow_buffers fs/buffer.c:1054 [inline] __getblk_slow fs/buffer.c:1081 [inline] __getblk_gfp+0x217/0x7d0 fs/buffer.c:1376 sb_getblk include/linux/buffer_head.h:356 [inline] ext4_getblk+0x26c/0x6d0 fs/ext4/inode.c:900 ext4_bread_batch+0x66/0x490 fs/ext4/inode.c:967 __ext4_find_entry+0xf83/0x1a70 fs/ext4/namei.c:1671 ext4_lookup_entry fs/ext4/namei.c:1774 [inline] ext4_lookup+0x144/0x6d0 fs/ext4/namei.c:1842 lookup_open fs/namei.c:3459 [inline] open_last_lookups fs/namei.c:3549 [inline] path_openat+0xff3/0x2f50 fs/namei.c:3779 do_filp_open+0x1c1/0x3c0 fs/namei.c:3809 do_sys_openat2+0x185/0x7e0 fs/open.c:1341 do_sys_open fs/open.c:1357 [inline] __do_sys_creat fs/open.c:1435 [inline] __se_sys_creat fs/open.c:1429 [inline] __x64_sys_creat+0x8e/0xb0 fs/open.c:1429 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1545 [inline] free_pcp_prepare mm/page_alloc.c:1619 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3581 free_unref_page_list+0xba/0x7c0 mm/page_alloc.c:3729 release_pages+0xad1/0xb20 mm/swap.c:1043 __pagevec_release+0x71/0xe0 mm/swap.c:1063 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x51a/0x1470 mm/shmem.c:955 shmem_truncate_range mm/shmem.c:1071 [inline] shmem_evict_inode+0x242/0xa10 mm/shmem.c:1180 evict+0x493/0x890 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x620/0x670 fs/inode.c:1860 dentry_unlink_inode+0x33d/0x3f0 fs/dcache.c:405 __dentry_kill+0x460/0x670 fs/dcache.c:611 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 do_renameat2+0x8ba/0xf60 fs/namei.c:5028 __do_sys_rename fs/namei.c:5072 [inline] __se_sys_rename fs/namei.c:5070 [inline] __x64_sys_rename+0x86/0x90 fs/namei.c:5070 x64_sys_call+0x300/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:83 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 Memory state around the buggy address: ffff888134ae7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888134ae7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888134ae8000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888134ae8080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888134ae8100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop1): ext4_dx_csum_set:531: inode #2: comm syz.1.169: dir seems corrupt? Run e2fsck -D.