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BUG: KASAN: slab-out-of-bounds in vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3275
Read of size 1 at addr ffff88809767aec3 by task syz-executor.4/28336

CPU: 0 PID: 28336 Comm: syz-executor.4 Not tainted 5.7.0-rc4-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 28336:
 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 4322:
 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_check_open_permission+0x6e2/0x900 security/tomoyo/file.c:786
 security_file_open+0x50/0xc0 security/security.c:1548
 do_dentry_open+0x35d/0x10b0 fs/open.c:784
 do_open fs/namei.c:3229 [inline]
 path_openat+0x2790/0x38b0 fs/namei.c:3346
 do_filp_open+0x191/0x3a0 fs/namei.c:3373
 do_sys_openat2+0x463/0x770 fs/open.c:1148
 do_sys_open fs/open.c:1164 [inline]
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_open fs/open.c:1170 [inline]
 __se_sys_open fs/open.c:1168 [inline]
 __x64_sys_open+0x1af/0x1e0 fs/open.c:1168
 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 ffff88809767ae80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 67 bytes inside of
 96-byte region [ffff88809767ae80, ffff88809767aee0)
The buggy address belongs to the page:
page:ffffea00025d9e80 refcount:1 mapcount:0 mapping:0000000085189a8c index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea000241a508 ffffea0002752dc8 ffff8880aa400540
raw: 0000000000000000 ffff88809767a000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809767ad80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
 ffff88809767ae00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
>ffff88809767ae80: 00 00 00 00 00 00 00 00 03 fc fc fc fc fc fc fc
                                           ^
 ffff88809767af00: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
 ffff88809767af80: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc
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