C++: Add a TaintFunction model to FormattingFunction.

This commit is contained in:
Geoffrey White
2020-01-24 17:25:09 +00:00
parent 1d46971bb7
commit 30580e97dc
5 changed files with 22 additions and 2 deletions

View File

@@ -7,6 +7,7 @@
*/
import semmle.code.cpp.models.interfaces.ArrayFunction
import semmle.code.cpp.models.interfaces.Taint
private Type stripTopLevelSpecifiersOnly(Type t) {
result = stripTopLevelSpecifiersOnly(t.(SpecifiedType).getBaseType())
@@ -39,7 +40,7 @@ private Type getAFormatterWideTypeOrDefault() {
/**
* A standard library function that uses a `printf`-like formatting string.
*/
abstract class FormattingFunction extends ArrayFunction {
abstract class FormattingFunction extends ArrayFunction, TaintFunction {
/** Gets the position at which the format parameter occurs. */
abstract int getFormatParameterIndex();
@@ -155,4 +156,9 @@ abstract class FormattingFunction extends ArrayFunction {
predicate hasArrayOutput(int bufParam) {
bufParam = getOutputParameterIndex()
}
override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
input.isParameterDeref(getFormatParameterIndex()) and
output.isParameterDeref(getOutputParameterIndex())
}
}

View File

@@ -55,7 +55,7 @@ void test1()
{
char buffer[256] = {0};
sink(snprintf(buffer, 256, string::source(), "Hello."));
sink(buffer); // tainted [NOT DETECTED]
sink(buffer); // tainted
}
{
char buffer[256] = {0};

View File

@@ -11,50 +11,62 @@
| format.cpp:46:21:46:24 | {...} | format.cpp:48:8:48:13 | buffer | |
| format.cpp:46:23:46:23 | 0 | format.cpp:46:21:46:24 | {...} | TAINT |
| format.cpp:47:17:47:22 | ref arg buffer | format.cpp:48:8:48:13 | buffer | |
| format.cpp:47:30:47:33 | %s | format.cpp:47:17:47:22 | ref arg buffer | TAINT |
| format.cpp:51:21:51:24 | {...} | format.cpp:52:17:52:22 | buffer | |
| format.cpp:51:21:51:24 | {...} | format.cpp:53:8:53:13 | buffer | |
| format.cpp:51:23:51:23 | 0 | format.cpp:51:21:51:24 | {...} | TAINT |
| format.cpp:52:17:52:22 | ref arg buffer | format.cpp:53:8:53:13 | buffer | |
| format.cpp:52:30:52:33 | %s | format.cpp:52:17:52:22 | ref arg buffer | TAINT |
| format.cpp:56:21:56:24 | {...} | format.cpp:57:17:57:22 | buffer | |
| format.cpp:56:21:56:24 | {...} | format.cpp:58:8:58:13 | buffer | |
| format.cpp:56:23:56:23 | 0 | format.cpp:56:21:56:24 | {...} | TAINT |
| format.cpp:57:17:57:22 | ref arg buffer | format.cpp:58:8:58:13 | buffer | |
| format.cpp:57:30:57:43 | call to source | format.cpp:57:17:57:22 | ref arg buffer | TAINT |
| format.cpp:61:21:61:24 | {...} | format.cpp:62:17:62:22 | buffer | |
| format.cpp:61:21:61:24 | {...} | format.cpp:63:8:63:13 | buffer | |
| format.cpp:61:23:61:23 | 0 | format.cpp:61:21:61:24 | {...} | TAINT |
| format.cpp:62:17:62:22 | ref arg buffer | format.cpp:63:8:63:13 | buffer | |
| format.cpp:62:30:62:39 | %s %s %s | format.cpp:62:17:62:22 | ref arg buffer | TAINT |
| format.cpp:66:21:66:24 | {...} | format.cpp:67:17:67:22 | buffer | |
| format.cpp:66:21:66:24 | {...} | format.cpp:68:8:68:13 | buffer | |
| format.cpp:66:23:66:23 | 0 | format.cpp:66:21:66:24 | {...} | TAINT |
| format.cpp:67:17:67:22 | ref arg buffer | format.cpp:68:8:68:13 | buffer | |
| format.cpp:67:30:67:35 | %.*s | format.cpp:67:17:67:22 | ref arg buffer | TAINT |
| format.cpp:72:21:72:24 | {...} | format.cpp:73:17:73:22 | buffer | |
| format.cpp:72:21:72:24 | {...} | format.cpp:74:8:74:13 | buffer | |
| format.cpp:72:23:72:23 | 0 | format.cpp:72:21:72:24 | {...} | TAINT |
| format.cpp:73:17:73:22 | ref arg buffer | format.cpp:74:8:74:13 | buffer | |
| format.cpp:73:30:73:33 | %i | format.cpp:73:17:73:22 | ref arg buffer | TAINT |
| format.cpp:77:21:77:24 | {...} | format.cpp:78:17:78:22 | buffer | |
| format.cpp:77:21:77:24 | {...} | format.cpp:79:8:79:13 | buffer | |
| format.cpp:77:23:77:23 | 0 | format.cpp:77:21:77:24 | {...} | TAINT |
| format.cpp:78:17:78:22 | ref arg buffer | format.cpp:79:8:79:13 | buffer | |
| format.cpp:78:30:78:33 | %i | format.cpp:78:17:78:22 | ref arg buffer | TAINT |
| format.cpp:82:21:82:24 | {...} | format.cpp:83:17:83:22 | buffer | |
| format.cpp:82:21:82:24 | {...} | format.cpp:84:8:84:13 | buffer | |
| format.cpp:82:23:82:23 | 0 | format.cpp:82:21:82:24 | {...} | TAINT |
| format.cpp:83:17:83:22 | ref arg buffer | format.cpp:84:8:84:13 | buffer | |
| format.cpp:83:30:83:35 | %.*s | format.cpp:83:17:83:22 | ref arg buffer | TAINT |
| format.cpp:88:21:88:24 | {...} | format.cpp:89:17:89:22 | buffer | |
| format.cpp:88:21:88:24 | {...} | format.cpp:90:8:90:13 | buffer | |
| format.cpp:88:23:88:23 | 0 | format.cpp:88:21:88:24 | {...} | TAINT |
| format.cpp:89:17:89:22 | ref arg buffer | format.cpp:90:8:90:13 | buffer | |
| format.cpp:89:30:89:33 | %p | format.cpp:89:17:89:22 | ref arg buffer | TAINT |
| format.cpp:94:21:94:24 | {...} | format.cpp:95:16:95:21 | buffer | |
| format.cpp:94:21:94:24 | {...} | format.cpp:96:8:96:13 | buffer | |
| format.cpp:94:23:94:23 | 0 | format.cpp:94:21:94:24 | {...} | TAINT |
| format.cpp:95:16:95:21 | ref arg buffer | format.cpp:96:8:96:13 | buffer | |
| format.cpp:95:24:95:27 | %s | format.cpp:95:16:95:21 | ref arg buffer | TAINT |
| format.cpp:99:21:99:24 | {...} | format.cpp:100:16:100:21 | buffer | |
| format.cpp:99:21:99:24 | {...} | format.cpp:101:8:101:13 | buffer | |
| format.cpp:99:23:99:23 | 0 | format.cpp:99:21:99:24 | {...} | TAINT |
| format.cpp:100:16:100:21 | ref arg buffer | format.cpp:101:8:101:13 | buffer | |
| format.cpp:100:24:100:28 | %ls | format.cpp:100:16:100:21 | ref arg buffer | TAINT |
| format.cpp:104:25:104:28 | {...} | format.cpp:105:17:105:23 | wbuffer | |
| format.cpp:104:25:104:28 | {...} | format.cpp:106:8:106:14 | wbuffer | |
| format.cpp:104:27:104:27 | 0 | format.cpp:104:25:104:28 | {...} | TAINT |
| format.cpp:105:17:105:23 | ref arg wbuffer | format.cpp:106:8:106:14 | wbuffer | |
| format.cpp:105:31:105:35 | %s | format.cpp:105:17:105:23 | ref arg wbuffer | TAINT |
| format.cpp:109:21:109:24 | {...} | format.cpp:110:18:110:23 | buffer | |
| format.cpp:109:21:109:24 | {...} | format.cpp:111:8:111:13 | buffer | |
| format.cpp:109:23:109:23 | 0 | format.cpp:109:21:109:24 | {...} | TAINT |

View File

@@ -1,3 +1,4 @@
| format.cpp:58:8:58:13 | buffer | format.cpp:57:30:57:43 | call to source |
| taint.cpp:8:8:8:13 | clean1 | taint.cpp:4:27:4:33 | source1 |
| taint.cpp:16:8:16:14 | source1 | taint.cpp:12:22:12:27 | call to source |
| taint.cpp:17:8:17:16 | ++ ... | taint.cpp:12:22:12:27 | call to source |

View File

@@ -1,3 +1,4 @@
| format.cpp:58:8:58:13 | format.cpp:57:30:57:43 | AST only |
| taint.cpp:41:7:41:13 | taint.cpp:35:12:35:17 | AST only |
| taint.cpp:42:7:42:13 | taint.cpp:35:12:35:17 | AST only |
| taint.cpp:43:7:43:13 | taint.cpp:37:22:37:27 | AST only |