CVE request: an invalid pointer read in mini-xml 2.7

[Gustavo Grieco <gustavo.grieco () gmail com>]

Hi,

An invalid pointer read located in a vsnprintf call in mini-xml 2.7 (
https://www.msweet.org/projects.php?Z3) was found:

$ gdb --args ./testmxml jezrijgasv.xml.-5377691366552468283
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff48b3a03 in _IO_vfprintf_internal (s=s@entry=0x7fffffff9970,
format=<optimized out>,
    format@entry=0x40d900 "<%s> cannot be a second root node after <%s>",
ap=ap@entry=0x7fffffff9b10) at vfprintf.c:1661
1661    vfprintf.c: No such file or directory.
(gdb) bt
#0  0x00007ffff48b3a03 in _IO_vfprintf_internal (s=s@entry=0x7fffffff9970,
format=<optimized out>,
    format@entry=0x40d900 "<%s> cannot be a second root node after <%s>",
ap=ap@entry=0x7fffffff9b10) at vfprintf.c:1661
#1  0x00007ffff4971235 in ___vsnprintf_chk (s=s@entry=0x7fffffff9b50 "<b>
cannot be a second root node after <\002", maxlen=<optimized out>,
    maxlen@entry=1024, flags=flags@entry=1, slen=slen@entry=1024,
format=format@entry=0x40d900 "<%s> cannot be a second root node after
<%s>",
    args=args@entry=0x7fffffff9b10) at vsnprintf_chk.c:63
#2  0x000000000040a3c0 in vsnprintf (__ap=0x7fffffff9b10, __fmt=0x40d900
"<%s> cannot be a second root node after <%s>", __n=1024,
    __s=0x7fffffff9b50 "<b> cannot be a second root node after <\002") at
/usr/include/x86_64-linux-gnu/bits/stdio2.h:77
#3  mxml_error (format=0x40d900 "<%s> cannot be a second root node after
<%s>") at mxml-private.c:86
#4  0x0000000000405a74 in mxml_load_data (top=top@entry=0x0,
p=p@entry=0x60360000fd80,
cb=cb@entry=0x402863 <type_cb>,
    getc_cb=getc_cb@entry=0x404c78 <mxml_file_getc>, sax_cb=sax_cb@entry=0x0,
sax_data=sax_data@entry=0x0) at mxml-file.c:1662
#5  0x00000000004079d0 in mxmlLoadFile (top=top@entry=0x0,
fp=fp@entry=0x60360000fd80,
cb=cb@entry=0x402863 <type_cb>) at mxml-file.c:199
#6  0x0000000000402166 in main (argc=<optimized out>, argv=0x7fffffffe4f8)
at testmxml.c:473

Fortunately, this issue is fixed in mini-xml 2.9. A reproducer is available
upon request. Please assign a CVE if necesary.

Regards,
Gustavo.