================================================================== BUG: KASAN: slab-out-of-bounds in vsscanf+0x2666/0x2ef0 lib/vsprintf.c:3275 Read of size 1 at addr ffff88809681ef03 by task syz-executor.5/16331 CPU: 0 PID: 16331 Comm: syz-executor.5 Not tainted 5.7.0-rc1-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 16331: 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 __kernel_write+0x120/0x350 fs/read_write.c:516 write_pipe_buf+0xf9/0x150 fs/splice.c:809 splice_from_pipe_feed fs/splice.c:512 [inline] __splice_from_pipe+0x329/0x870 fs/splice.c:636 splice_from_pipe fs/splice.c:671 [inline] default_file_splice_write+0x112/0x1b0 fs/splice.c:821 splice_direct_to_actor+0x482/0xb40 fs/splice.c:992 do_splice_direct+0x201/0x340 fs/splice.c:1080 do_sendfile+0x809/0xfe0 fs/read_write.c:1521 __do_sys_sendfile64 fs/read_write.c:1582 [inline] __se_sys_sendfile64 fs/read_write.c:1568 [inline] __x64_sys_sendfile64+0x164/0x1a0 fs/read_write.c:1568 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 15923: 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_path_perm+0x56b/0x740 security/tomoyo/file.c:840 tomoyo_path_symlink+0x91/0xc0 security/tomoyo/tomoyo.c:206 security_path_symlink+0xd6/0x160 security/security.c:1104 do_symlinkat+0xeb/0x420 fs/namei.c:3962 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 ffff88809681ef00 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 3 bytes inside of 32-byte region [ffff88809681ef00, ffff88809681ef20) The buggy address belongs to the page: page:ffffea00025a0780 refcount:1 mapcount:0 mapping:000000001c3dbb0e index:0xffff88809681efc1 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002933248 ffffea00027bbb88 ffff8880aa4001c0 raw: ffff88809681efc1 ffff88809681e000 000000010000003f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809681ee00: 05 fc fc fc fc fc fc fc 00 00 01 fc fc fc fc fc ffff88809681ee80: 00 00 01 fc fc fc fc fc 05 fc fc fc fc fc fc fc >ffff88809681ef00: 03 fc fc fc fc fc fc fc 00 01 fc fc fc fc fc fc ^ ffff88809681ef80: 05 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88809681f000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ==================================================================