Re: questionable `sprintf` usage

[He Zhenxing]

Hi,

sprintf function can be called with only 2 arguments if there is no 
format specifiers in the second argument (template).

So the following two are identical:

char *s = "some string";

sprintf(target, s);

sprintf(target, "%s", s);

But of course, sprintf is usually not recommended because it does not 
check for the buffer length, which may lead to buffer overflow and cause 
problems that are hard to find.

He Zhenxing

在 2018/12/19 下午6:34, wenjun....@esgyn.cn 写道:
Hi,

  

I suspect the following code in core/sql/ustat/hs_read.cpp is erroneous:

2120   desc = new SQLDESC_ID;

2121   init_SQLCLI_OBJ_ID(desc);

2122

2123   desc->name_mode = cursor_name;

2124   desc->module = &module;

2125   desc->identifier = new char[HS_STMTID_LENGTH];

2126   desc->handle     = 0;

2127

2128   sprintf((char*)desc->identifier, descID);

2129   desc->identifier_len = strlen(descID);

  

The parameters to function `sprintf` should be 3, but there are only 2.

  

I’d like to change it to:

        snprintf((char*)desc->identifier, HS_STMTID_LENGTH, “%s”, descID);

  

How do you find it?

  

Regards,

Wenjun Zhu