==================================================================
BUG: KASAN: slab-out-of-bounds in vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3321
Read of size 1 at addr ffff888094269603 by task syz-executor.0/9752

CPU: 0 PID: 9752 Comm: syz-executor.0 Not tainted 5.7.0-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+0x66/0x5a0 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3321
 sscanf+0x6c/0x90 lib/vsprintf.c:3527
 smk_set_cipso+0x1ac/0x6a0 security/smack/smackfs.c:881
 do_loop_readv_writev fs/read_write.c:718 [inline]
 do_iter_write+0x402/0x540 fs/read_write.c:1001
 vfs_writev fs/read_write.c:1072 [inline]
 do_writev+0x23f/0x4a0 fs/read_write.c:1115
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca69
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f33cb00ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000050d680 RCX: 000000000045ca69
RDX: 0000000000000001 RSI: 00000000200003c0 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000d20 R14: 00000000004cb4a9 R15: 00007f33cb00b6d4

Allocated by task 9752:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494
 __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
 do_loop_readv_writev fs/read_write.c:718 [inline]
 do_iter_write+0x402/0x540 fs/read_write.c:1001
 vfs_writev fs/read_write.c:1072 [inline]
 do_writev+0x23f/0x4a0 fs/read_write.c:1115
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 9216:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x220 mm/slab.c:3757
 tomoyo_path_number_perm+0x525/0x690 security/tomoyo/file.c:736
 security_file_ioctl+0x55/0xb0 security/security.c:1460
 ksys_ioctl fs/ioctl.c:765 [inline]
 __do_sys_ioctl fs/ioctl.c:780 [inline]
 __se_sys_ioctl+0x48/0x160 fs/ioctl.c:778
 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 ffff888094269600
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 3 bytes inside of
 32-byte region [ffff888094269600, ffff888094269620)
The buggy address belongs to the page:
page:ffffea0002509a40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888094269fc1
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002766b08 ffffea000239c2c8 ffff8880aa4001c0
raw: ffff888094269fc1 ffff888094269000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888094269500: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff888094269580: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff888094269600: 03 fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
                   ^
 ffff888094269680: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff888094269700: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================