Fixed ticket #570 (Buffer overrun not detected when sprintf() format string greater then buffer size)

http://sourceforge.net/apps/trac/cppcheck/ticket/570
This commit is contained in:
Slava Semushin 2009-08-08 21:52:35 +07:00
parent 92d4c086ce
commit 0f96299d87
2 changed files with 44 additions and 2 deletions

View File

@ -382,11 +382,36 @@ void CheckBufferOverrun::checkScope(const Token *tok, const char *varname[], con
// sprintf.. // sprintf..
if (varid > 0 && Token::Match(tok, "sprintf ( %varid% , %str% ,", varid)) if (varid > 0 && Token::Match(tok, "sprintf ( %varid% , %str% [,)]", varid))
{ {
int len = 0; int len = -2;
const Token *end = tok->next()->link(); const Token *end = tok->next()->link();
// check format string
const char *fmt = tok->strAt(4);
while (*fmt)
{
if (*fmt == '\\')
{
++fmt;
}
else if (*fmt == '%')
{
// FIXME: better handling for format specifiers
fmt += 2;
continue;
}
++fmt;
++len;
}
if (len >= (int)size)
{
bufferOverrun(tok);
}
// check arguments
len = 0;
for (const Token *tok2 = tok->tokAt(6); tok2 && tok2 != end; tok2 = tok2->next()) for (const Token *tok2 = tok->tokAt(6); tok2 && tok2 != end; tok2 = tok2->next())
{ {
if (tok2->str()[0] == '\"') if (tok2->str()[0] == '\"')

View File

@ -95,6 +95,7 @@ private:
TEST_CASE(sprintf1); TEST_CASE(sprintf1);
TEST_CASE(sprintf2); TEST_CASE(sprintf2);
TEST_CASE(sprintf3);
TEST_CASE(snprintf1); TEST_CASE(snprintf1);
TEST_CASE(snprintf2); TEST_CASE(snprintf2);
@ -573,7 +574,23 @@ private:
" sprintf(str, \"%d: %s\", getnumber(), \"abcde\");\n" " sprintf(str, \"%d: %s\", getnumber(), \"abcde\");\n"
"}\n"); "}\n");
ASSERT_EQUALS("[test.cpp:4]: (possible error) Buffer overrun\n", errout.str()); ASSERT_EQUALS("[test.cpp:4]: (possible error) Buffer overrun\n", errout.str());
}
void sprintf3()
{
check("void f()\n"
"{\n"
" char str[3];\n"
" sprintf(str, \"test\");\n"
"}\n");
ASSERT_EQUALS("[test.cpp:4]: (possible error) Buffer overrun\n", errout.str());
check("void f()\n"
"{\n"
" char str[5];\n"
" sprintf(str, \"test%s\", "");\n"
"}\n");
ASSERT_EQUALS("", errout.str());
} }
void snprintf1() void snprintf1()