==================================================================
BUG: KASAN: use-after-free in dx_insert_block fs/ext4/namei.c:1358 [inline]
BUG: KASAN: use-after-free in do_split+0x19d7/0x1e90 fs/ext4/namei.c:2044
Read of size 157024 at addr ffff8881324bd028 by task syz.3.141/958

CPU: 1 PID: 958 Comm: syz.3.141 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x100/0x140 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 memmove+0x2d/0x70 mm/kasan/shadow.c:54
 dx_insert_block fs/ext4/namei.c:1358 [inline]
 do_split+0x19d7/0x1e90 fs/ext4/namei.c:2044
 make_indexed_dir+0xe14/0x1460 fs/ext4/namei.c:2348
 ext4_add_entry+0xd80/0xf90 fs/ext4/namei.c:2460
 __ext4_link+0x4d6/0x760 fs/ext4/namei.c:3647
 ext4_link+0x1ee/0x290 fs/ext4/namei.c:3688
 vfs_link+0x684/0x880 fs/namei.c:4263
 do_linkat+0x381/0x670 fs/namei.c:4331
 __do_sys_link fs/namei.c:4360 [inline]
 __se_sys_link fs/namei.c:4358 [inline]
 __x64_sys_link+0x68/0x80 fs/namei.c:4358
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fad206b23b9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fad20121028 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007fad208b7fa0 RCX: 00007fad206b23b9
RDX: 0000000000000000 RSI: 0000000020000bc0 RDI: 0000000020001240
RBP: 00007fad2073d9d4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fad208b7fa0 R15: 00007ffe10b257a8

The buggy address belongs to the page:
page:ffffea0004c92f40 refcount:3 mapcount:1 mapping:ffff888110757e10 index:0x1 pfn:0x1324bd
aops:def_blk_aops ino:0
flags: 0x400000000032201e(referenced|uptodate|dirty|lru|private|mappedtodisk|unevictable|mlocked)
raw: 400000000032201e ffffea0004441a08 ffffea0004752e48 ffff888110757e10
raw: 0000000000000001 ffff888110716e70 0000000300000000 ffff8881292ce000
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8881292ce000
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48(GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), pid 958, ts 78844709769, free_ts 78828865324
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x176/0x190 mm/page_alloc.c:2462
 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
 __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]
 __page_cache_alloc include/linux/pagemap.h:290 [inline]
 pagecache_get_page+0x63e/0x930 mm/filemap.c:1848
 find_or_create_page include/linux/pagemap.h:402 [inline]
 grow_dev_page fs/buffer.c:976 [inline]
 grow_buffers fs/buffer.c:1045 [inline]
 __getblk_slow fs/buffer.c:1072 [inline]
 __getblk_gfp+0x212/0x780 fs/buffer.c:1370
 sb_getblk include/linux/buffer_head.h:361 [inline]
 ext4_getblk fs/ext4/inode.c:880 [inline]
 ext4_bread_batch+0x1de/0x790 fs/ext4/inode.c:946
 __ext4_find_entry+0xf1f/0x1930 fs/ext4/namei.c:1643
 ext4_lookup_entry fs/ext4/namei.c:1746 [inline]
 ext4_lookup+0x305/0x8c0 fs/ext4/namei.c:1814
 lookup_open fs/namei.c:3276 [inline]
 open_last_lookups fs/namei.c:3367 [inline]
 path_openat+0x145d/0x3040 fs/namei.c:3556
 do_filp_open+0x1df/0x400 fs/namei.c:3586
 do_sys_openat2+0x19f/0x750 fs/open.c:1219
 do_sys_open fs/open.c:1235 [inline]
 __do_sys_creat fs/open.c:1311 [inline]
 __se_sys_creat fs/open.c:1305 [inline]
 __x64_sys_creat+0x8e/0xb0 fs/open.c:1305
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
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+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x129/0x9c0 mm/page_alloc.c:3443
 release_pages+0xe41/0xe90 mm/swap.c:1103
 __pagevec_release+0x71/0xe0 mm/swap.c:1123
 pagevec_release include/linux/pagevec.h:88 [inline]
 shmem_undo_range+0x741/0x1740 mm/shmem.c:965
 shmem_truncate_range mm/shmem.c:1069 [inline]
 shmem_evict_inode+0x1dc/0x970 mm/shmem.c:1169
 evict+0x4a9/0x940 fs/inode.c:612
 iput_final fs/inode.c:1736 [inline]
 iput+0x654/0x7e0 fs/inode.c:1762
 dentry_unlink_inode+0x2d5/0x390 fs/dcache.c:378
 __dentry_kill+0x45b/0x660 fs/dcache.c:583
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:883
 __fput+0x4bd/0x730 fs/file_table.c:294
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:175

Memory state around the buggy address:
 ffff8881324c2f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881324c2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881324c3000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881324c3080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881324c3100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
EXT4-fs error (device loop3): ext4_dx_csum_set:529: inode #2: comm syz.3.141: dir seems corrupt?  Run e2fsck -D.