Fix xslt_process() to ensure that it inserts a NULL terminator after the

last pair of parameter name/value strings, even when there are MAXPARAMS
of them.  Aboriginal bug in contrib/xml2, noted while studying bug #4912
(though I'm not sure whether there's something else involved in that
report).

This might be thought a security issue, since it's a potential backend
crash; but considering that untrustworthy users shouldn't be allowed
to get their hands on xslt_process() anyway, it's probably not worth
getting excited about.
This commit is contained in:
Tom Lane 2009-07-10 00:32:00 +00:00
parent b11ce5608a
commit e7370babd1
1 changed files with 12 additions and 8 deletions

View File

@ -1,5 +1,5 @@
/*
* $PostgreSQL: pgsql/contrib/xml2/xslt_proc.c,v 1.15 2009/06/11 14:48:53 momjian Exp $
* $PostgreSQL: pgsql/contrib/xml2/xslt_proc.c,v 1.16 2009/07/10 00:32:00 tgl Exp $
*
* XSLT processing functions (requiring libxslt)
*
@ -38,7 +38,8 @@ static void parse_params(const char **params, text *paramstr);
Datum xslt_process(PG_FUNCTION_ARGS);
#define MAXPARAMS 20
#define MAXPARAMS 20 /* must be even, see parse_params() */
PG_FUNCTION_INFO_V1(xslt_process);
@ -129,12 +130,11 @@ xslt_process(PG_FUNCTION_ARGS)
}
void
static void
parse_params(const char **params, text *paramstr)
{
char *pos;
char *pstr;
int i;
char *nvsep = "=";
char *itsep = ",";
@ -154,11 +154,13 @@ parse_params(const char **params, text *paramstr)
}
else
{
params[i] = NULL;
/* No equal sign, so ignore this "parameter" */
/* We'll reset params[i] to NULL below the loop */
break;
}
/* Value */
i++;
/* since MAXPARAMS is even, we still have i < MAXPARAMS */
params[i] = pos;
pos = strstr(pos, itsep);
if (pos != NULL)
@ -167,9 +169,11 @@ parse_params(const char **params, text *paramstr)
pos++;
}
else
{
i++;
break;
}
}
if (i < MAXPARAMS)
params[i + 1] = NULL;
params[i] = NULL;
}