It exists a buffer overflow when use wbook_addworksheet()

[fantasyoung]

Description

When specify the second parameter ，it will be buffer overflow

My test program

example1.zip

Command and argument

gcc -fsanitize=address -ggdb -o exampletest example1.c ../src/*.c -I ../include/

Crash Information

The output of exampletest with address sanitizer enabled

ASAN:SIGSEGV
=================================================================
==81551==ERROR: AddressSanitizer: SEGV on unknown address 0x000000410fff (pc 0x00000040b77a bp 0x7fff3f8f7ce0 sp 0x7fff3f8f7cb0 T0)
    #0 0x40b779 in wbook_addworksheet ../src/workbook.c:123
    #1 0x401248 in main /home/wind/libexcel/libexcel-master/tests/example1.c:31
    #2 0x7ff81e38c82f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f)
    #3 0x401148 in _start (/home/wind/libexcel/libexcel-master/tests/exampletest+0x401148)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV ../src/workbook.c:123 wbook_addworksheet
==81551==ABORTING

CREDIT

pu!m,Huawei Weiran Labs

[abergmann]

CVE-2018-20304 was assigned to this issue.