Merge pull request #2657 from jbj/DefaultTaintTracking-models

C++: wire up models library to DefaultTaintTracking
This commit is contained in:
Robert Marsh
2020-01-27 17:41:54 -05:00
committed by GitHub
10 changed files with 302 additions and 103 deletions

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@@ -0,0 +1,41 @@
int atoi(const char *nptr);
char *getenv(const char *name);
char *strcat(char * s1, const char * s2);
char *strdup(const char *);
char *_strdup(const char *);
char *unmodeled_function(const char *);
void sink(const char *);
void sink(int);
int main(int argc, char *argv[]) {
sink(_strdup(getenv("VAR")));
sink(strdup(getenv("VAR")));
sink(unmodeled_function(getenv("VAR")));
char untainted_buf[100] = "";
char buf[100] = "VAR = ";
sink(strcat(buf, getenv("VAR")));
sink(buf); // BUG: no taint
sink(untainted_buf); // the two buffers would be conflated if we added flow through partial chi inputs
return 0;
}
typedef unsigned int inet_addr_retval;
inet_addr_retval inet_addr(const char *dotted_address);
void sink(inet_addr_retval);
void test_indirect_arg_to_model() {
// This test is non-sensical but carefully arranged so we get data flow into
// inet_addr not through the function argument but through its associated
// read side effect.
void *env_pointer = getenv("VAR"); // env_pointer is tainted, not its data.
inet_addr_retval a = inet_addr((const char *)&env_pointer);
sink(a);
}

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@@ -0,0 +1,29 @@
| defaulttainttracking.cpp:16:16:16:21 | call to getenv | defaulttainttracking.cpp:6:15:6:24 | p#0 |
| defaulttainttracking.cpp:16:16:16:21 | call to getenv | defaulttainttracking.cpp:9:11:9:20 | p#0 |
| defaulttainttracking.cpp:16:16:16:21 | call to getenv | defaulttainttracking.cpp:16:8:16:14 | call to _strdup |
| defaulttainttracking.cpp:16:16:16:21 | call to getenv | defaulttainttracking.cpp:16:8:16:29 | (const char *)... |
| defaulttainttracking.cpp:16:16:16:21 | call to getenv | defaulttainttracking.cpp:16:16:16:21 | call to getenv |
| defaulttainttracking.cpp:16:16:16:21 | call to getenv | defaulttainttracking.cpp:16:16:16:28 | (const char *)... |
| defaulttainttracking.cpp:17:15:17:20 | call to getenv | defaulttainttracking.cpp:5:14:5:23 | p#0 |
| defaulttainttracking.cpp:17:15:17:20 | call to getenv | defaulttainttracking.cpp:9:11:9:20 | p#0 |
| defaulttainttracking.cpp:17:15:17:20 | call to getenv | defaulttainttracking.cpp:17:8:17:13 | call to strdup |
| defaulttainttracking.cpp:17:15:17:20 | call to getenv | defaulttainttracking.cpp:17:8:17:28 | (const char *)... |
| defaulttainttracking.cpp:17:15:17:20 | call to getenv | defaulttainttracking.cpp:17:15:17:20 | call to getenv |
| defaulttainttracking.cpp:17:15:17:20 | call to getenv | defaulttainttracking.cpp:17:15:17:27 | (const char *)... |
| defaulttainttracking.cpp:18:27:18:32 | call to getenv | defaulttainttracking.cpp:7:26:7:35 | p#0 |
| defaulttainttracking.cpp:18:27:18:32 | call to getenv | defaulttainttracking.cpp:18:27:18:32 | call to getenv |
| defaulttainttracking.cpp:18:27:18:32 | call to getenv | defaulttainttracking.cpp:18:27:18:39 | (const char *)... |
| defaulttainttracking.cpp:22:20:22:25 | call to getenv | defaulttainttracking.cpp:3:38:3:39 | s2 |
| defaulttainttracking.cpp:22:20:22:25 | call to getenv | defaulttainttracking.cpp:9:11:9:20 | p#0 |
| defaulttainttracking.cpp:22:20:22:25 | call to getenv | defaulttainttracking.cpp:22:8:22:13 | call to strcat |
| defaulttainttracking.cpp:22:20:22:25 | call to getenv | defaulttainttracking.cpp:22:8:22:33 | (const char *)... |
| defaulttainttracking.cpp:22:20:22:25 | call to getenv | defaulttainttracking.cpp:22:20:22:25 | call to getenv |
| defaulttainttracking.cpp:22:20:22:25 | call to getenv | defaulttainttracking.cpp:22:20:22:32 | (const char *)... |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:32:11:32:26 | p#0 |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:38:11:38:21 | env_pointer |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:38:25:38:30 | call to getenv |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:38:25:38:37 | (void *)... |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:39:22:39:22 | a |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:39:26:39:34 | call to inet_addr |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:39:50:39:61 | & ... |
| defaulttainttracking.cpp:38:25:38:30 | call to getenv | defaulttainttracking.cpp:40:10:40:10 | a |

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@@ -0,0 +1,5 @@
import semmle.code.cpp.ir.dataflow.DefaultTaintTracking
from Expr source, Element tainted
where tainted(source, tainted)
select source, tainted