==================================================================
BUG: KASAN: slab-out-of-bounds in vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3275
Read of size 1 at addr ffff88804a7a7a2b by task syz-executor.3/18323

CPU: 1 PID: 18323 Comm: syz-executor.3 Not tainted 5.7.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1e9/0x30e lib/dump_stack.c:118
 print_address_description+0x74/0x5c0 mm/kasan/report.c:382
 __kasan_report+0x103/0x1a0 mm/kasan/report.c:511
 kasan_report+0x4d/0x80 mm/kasan/common.c:625

Allocated by task 18323:
 save_stack mm/kasan/common.c:49 [inline]
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc+0x114/0x160 mm/kasan/common.c:495
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc_track_caller+0x249/0x320 mm/slab.c:3671
 memdup_user_nul+0x26/0xf0 mm/util.c:259
 smk_set_cipso+0xff/0x6a0 security/smack/smackfs.c:859
 __vfs_write+0xa7/0x710 fs/read_write.c:495
 vfs_write+0x274/0x580 fs/read_write.c:559
 ksys_write+0x11b/0x220 fs/read_write.c:612
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 17425:
 save_stack mm/kasan/common.c:49 [inline]
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0x125/0x190 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x220 mm/slab.c:3757
 tomoyo_path2_perm+0x752/0x940 security/tomoyo/file.c:946
 tomoyo_path_rename+0xee/0x120 security/tomoyo/tomoyo.c:285
 security_path_rename+0x21b/0x2e0 security/security.c:1130
 do_renameat2+0x76e/0x1050 fs/namei.c:4433
 __do_sys_rename fs/namei.c:4483 [inline]
 __se_sys_rename fs/namei.c:4481 [inline]
 __x64_sys_rename+0x64/0x70 fs/namei.c:4481
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff88804a7a7a00
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 43 bytes inside of
 64-byte region [ffff88804a7a7a00, ffff88804a7a7a40)
The buggy address belongs to the page:
page:ffffea000129e9c0 refcount:1 mapcount:0 mapping:000000000f4baf38 index:0xffff88804a7a7380
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00027b2708 ffffea00025bb988 ffff8880aa400380
raw: ffff88804a7a7380 ffff88804a7a7000 0000000100000018 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88804a7a7900: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88804a7a7980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88804a7a7a00: 00 00 00 00 00 03 fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff88804a7a7a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88804a7a7b00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================