xref: /llvm-project/clang/test/Analysis/taint-diagnostic-visitor.c (revision 09b8dbfa80d62e64efb09bd166324270c96badf9)
1 // RUN: %clang_cc1 -analyze -analyzer-checker=optin.taint,core,alpha.security.ArrayBoundV2 -analyzer-output=text -verify %s
2 
3 // This file is for testing enhanced diagnostics produced by the GenericTaintChecker
4 
5 typedef __typeof(sizeof(int)) size_t;
6 struct _IO_FILE;
7 typedef struct _IO_FILE FILE;
8 
9 int scanf(const char *restrict format, ...);
10 int system(const char *command);
11 char* getenv( const char* env_var );
12 size_t strlen( const char* str );
13 char *strcat( char *dest, const char *src );
14 char* strcpy( char* dest, const char* src );
15 void *malloc(size_t size );
16 void free( void *ptr );
17 char *fgets(char *str, int n, FILE *stream);
18 extern FILE *stdin;
19 
20 void taintDiagnostic(void)
21 {
22   char buf[128];
23   scanf("%s", buf); // expected-note {{Taint originated here}}
24                     // expected-note@-1 {{Taint propagated to the 2nd argument}}
25   system(buf); // expected-warning {{Untrusted data is passed to a system call}} // expected-note {{Untrusted data is passed to a system call (CERT/STR02-C. Sanitize data passed to complex subsystems)}}
26 }
27 
28 int taintDiagnosticOutOfBound(void) {
29   int index;
30   int Array[] = {1, 2, 3, 4, 5};
31   scanf("%d", &index); // expected-note {{Taint originated here}}
32                        // expected-note@-1 {{Taint propagated to the 2nd argument}}
33   return Array[index]; // expected-warning {{Potential out of bound access to 'Array' with tainted index}}
34                        // expected-note@-1 {{Access of 'Array' with a tainted index}}
35 }
36 
37 int taintDiagnosticDivZero(int operand) {
38   scanf("%d", &operand); // expected-note {{Value assigned to 'operand'}}
39                          // expected-note@-1 {{Taint originated here}}
40                          // expected-note@-2 {{Taint propagated to the 2nd argument}}
41   return 10 / operand; // expected-warning {{Division by a tainted value, possibly zero}}
42                        // expected-note@-1 {{Division by a tainted value, possibly zero}}
43 }
44 
45 void taintDiagnosticVLA(void) {
46   int x;
47   scanf("%d", &x); // expected-note {{Value assigned to 'x'}}
48                    // expected-note@-1 {{Taint originated here}}
49                    // expected-note@-2 {{Taint propagated to the 2nd argument}}
50   int vla[x]; // expected-warning {{Declared variable-length array (VLA) has tainted}}
51               // expected-note@-1 {{Declared variable-length array (VLA) has tainted}}
52 }
53 
54 
55 // Tests if the originated note is correctly placed even if the path is
56 // propagating through variables and expressions
57 int taintDiagnosticPropagation(){
58   int res;
59   char *cmd=getenv("CMD"); // expected-note {{Taint originated here}}
60                            // expected-note@-1 {{Taint propagated to the return value}}
61   if (cmd){ // expected-note {{Assuming 'cmd' is non-null}}
62             // expected-note@-1 {{Taking true branch}}
63     res = system(cmd); // expected-warning{{Untrusted data is passed to a system call}}
64                        // expected-note@-1{{Untrusted data is passed to a system call}}
65     return res;
66   }
67   return -1;
68 }
69 
70 // Taint origin should be marked correctly even if there are multiple taint
71 // sources in the function
72 int taintDiagnosticPropagation2(){
73   int res;
74   char *user_env2=getenv("USER_ENV_VAR2");//unrelated taint source
75   char *cmd=getenv("CMD"); // expected-note {{Taint originated here}}
76                            // expected-note@-1 {{Taint propagated to the return value}}
77   char *user_env=getenv("USER_ENV_VAR");//unrelated taint source
78   if (cmd){ // expected-note {{Assuming 'cmd' is non-null}}
79 	          // expected-note@-1 {{Taking true branch}}
80     res = system(cmd); // expected-warning{{Untrusted data is passed to a system call}}
81                        // expected-note@-1{{Untrusted data is passed to a system call}}
82     return res;
83   }
84   return 0;
85 }
86 
87 void testReadStdIn(){
88   char buf[1024];
89   fgets(buf, sizeof(buf), stdin);// expected-note {{Taint originated here}}
90                                  // expected-note@-1 {{Taint propagated to the 1st argument}}
91   system(buf);// expected-warning {{Untrusted data is passed to a system call}}
92               // expected-note@-1 {{Untrusted data is passed to a system call (CERT/STR02-C. Sanitize data passed to complex subsystems)}}
93 
94 }
95 
96 void multipleTaintSources(void) {
97   char cmd[2048], file[1024];
98   scanf ("%1022[^\n] ", cmd); // expected-note {{Taint originated here}}
99                    // expected-note@-1 {{Taint propagated to the 2nd argument}}
100   scanf ("%1023[^\n]", file); // expected-note {{Taint originated here}}
101                    // expected-note@-1 {{Taint propagated to the 2nd argument}}
102   strcat(cmd, file); // expected-note {{Taint propagated to the 1st argument}}
103   strcat(cmd, " "); // expected-note {{Taint propagated to the 1st argument}}
104   system(cmd); // expected-warning {{Untrusted data is passed to a system call}}
105                // expected-note@-1{{Untrusted data is passed to a system call}}
106 }
107 
108 void multipleTaintedArgs(void) {
109   char cmd[1024], file[1024], buf[2048];
110   scanf("%1022s %1023s", cmd, file); // expected-note {{Taint originated here}}
111                           // expected-note@-1 {{Taint propagated to the 2nd argument, 3rd argument}}
112   strcpy(buf, cmd);// expected-note {{Taint propagated to the 1st argument}}
113   strcat(buf, " ");// expected-note {{Taint propagated to the 1st argument}}
114   strcat(buf, file);// expected-note {{Taint propagated to the 1st argument}}
115   system(buf); // expected-warning {{Untrusted data is passed to a system call}}
116                // expected-note@-1{{Untrusted data is passed to a system call}}
117 }
118 
119 void testTaintedMalloc(){
120   size_t size = 0;
121   scanf("%zu", &size); // expected-note {{Taint originated here}}
122                        // expected-note@-1 {{Taint propagated to the 2nd argument}}
123   int *p = malloc(size);// expected-warning{{malloc is called with a tainted (potentially attacker controlled) value}}
124                     // expected-note@-1{{malloc is called with a tainted (potentially attacker controlled) value}}
125   free(p);
126 }
127