1 //===-- sanitizer_format_interceptor_test.cpp -----------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Tests for *scanf interceptors implementation in sanitizer_common.
10 //
11 //===----------------------------------------------------------------------===//
12 #include <algorithm>
13 #include <vector>
14 
15 #include "interception/interception.h"
16 #include "sanitizer_test_utils.h"
17 #include "sanitizer_common/sanitizer_libc.h"
18 #include "sanitizer_common/sanitizer_common.h"
19 #include "gtest/gtest.h"
20 
21 using namespace __sanitizer;
22 
23 #define COMMON_INTERCEPTOR_READ_WRITE_RANGE(ctx, ptr, size)                    \
24   do {                                                                         \
25     ((std::vector<unsigned> *)ctx)->push_back(size);                           \
26     ptr = ptr;                                                                 \
27   } while (0)
28 
29 #define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size)                          \
30   COMMON_INTERCEPTOR_READ_WRITE_RANGE(ctx, ptr, size)
31 
32 #define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size)                         \
33   COMMON_INTERCEPTOR_READ_WRITE_RANGE(ctx, ptr, size)
34 
35 #define SANITIZER_INTERCEPT_PRINTF 1
36 #include "sanitizer_common/sanitizer_common_interceptors_format.inc"
37 
38 static const unsigned I = sizeof(int);
39 static const unsigned L = sizeof(long);
40 static const unsigned LL = sizeof(long long);
41 static const unsigned S = sizeof(short);
42 static const unsigned C = sizeof(char);
43 static const unsigned LC = sizeof(wchar_t);
44 static const unsigned D = sizeof(double);
45 static const unsigned LD = sizeof(long double);
46 static const unsigned F = sizeof(float);
47 static const unsigned P = sizeof(char *);
48 
verifyFormatResults(const char * format,unsigned n,const std::vector<unsigned> & computed_sizes,const std::vector<unsigned> & expected_sizes)49 static void verifyFormatResults(const char *format, unsigned n,
50                                 const std::vector<unsigned> &computed_sizes,
51                                 const std::vector<unsigned> &expected_sizes) {
52   // "+ 1" because of the format string
53   ASSERT_EQ(n + 1,
54             computed_sizes.size()) << "Unexpected number of format arguments: '"
55                                    << format << "'";
56   for (unsigned i = 0; i < n; ++i)
57     EXPECT_EQ(expected_sizes[i], computed_sizes[i + 1])
58         << "Unexpect write size for argument " << i << ", format string '"
59         << format << "'";
60 }
61 
62 static const char test_buf[] = "Test string.";
63 static const size_t test_buf_size = sizeof(test_buf);
64 
65 static const unsigned SCANF_ARGS_MAX = 16;
66 
testScanf3(void * ctx,int result,bool allowGnuMalloc,const char * format,...)67 static void testScanf3(void *ctx, int result, bool allowGnuMalloc,
68                        const char *format, ...) {
69   va_list ap;
70   va_start(ap, format);
71   scanf_common(ctx, result, allowGnuMalloc, format, ap);
72   va_end(ap);
73 }
74 
testScanf2(const char * format,int scanf_result,bool allowGnuMalloc,unsigned n,va_list expected_sizes_va)75 static void testScanf2(const char *format, int scanf_result,
76                        bool allowGnuMalloc, unsigned n,
77                        va_list expected_sizes_va) {
78   std::vector<unsigned> scanf_sizes, expected_sizes;
79   for (unsigned i = 0; i < n; ++i)
80     expected_sizes.push_back(va_arg(expected_sizes_va, unsigned));
81 
82   // 16 args should be enough.
83   testScanf3((void *)&scanf_sizes, scanf_result, allowGnuMalloc, format,
84              test_buf, test_buf, test_buf, test_buf, test_buf, test_buf,
85              test_buf, test_buf, test_buf, test_buf, test_buf, test_buf,
86              test_buf, test_buf, test_buf, test_buf);
87   verifyFormatResults(format, n, scanf_sizes, expected_sizes);
88 }
89 
testScanf(const char * format,unsigned n,...)90 static void testScanf(const char *format, unsigned n, ...) {
91   va_list ap;
92   va_start(ap, n);
93   testScanf2(format, SCANF_ARGS_MAX, /* allowGnuMalloc */ true, n, ap);
94   va_end(ap);
95 }
96 
testScanfPartial(const char * format,int scanf_result,unsigned n,...)97 static void testScanfPartial(const char *format, int scanf_result, unsigned n,
98                              ...) {
99   va_list ap;
100   va_start(ap, n);
101   testScanf2(format, scanf_result, /* allowGnuMalloc */ true,  n, ap);
102   va_end(ap);
103 }
104 
testScanfNoGnuMalloc(const char * format,unsigned n,...)105 static void testScanfNoGnuMalloc(const char *format, unsigned n, ...) {
106   va_list ap;
107   va_start(ap, n);
108   testScanf2(format, SCANF_ARGS_MAX, /* allowGnuMalloc */ false, n, ap);
109   va_end(ap);
110 }
111 
TEST(SanitizerCommonInterceptors,Scanf)112 TEST(SanitizerCommonInterceptors, Scanf) {
113   testScanf("%d", 1, I);
114   testScanf("%d%d%d", 3, I, I, I);
115   testScanf("ab%u%dc", 2, I, I);
116   testScanf("%ld", 1, L);
117   testScanf("%llu", 1, LL);
118   testScanf("%qd", 1, LL);
119   testScanf("a %hd%hhx", 2, S, C);
120   testScanf("%c", 1, C);
121   testScanf("%lc", 1, LC);
122 
123   testScanf("%%", 0);
124   testScanf("a%%", 0);
125   testScanf("a%%b", 0);
126   testScanf("a%%%%b", 0);
127   testScanf("a%%b%%", 0);
128   testScanf("a%%%%%%b", 0);
129   testScanf("a%%%%%b", 0);
130   testScanf("a%%%%%f", 1, F);
131   testScanf("a%%%lxb", 1, L);
132   testScanf("a%lf%%%lxb", 2, D, L);
133   testScanf("%nf", 1, I);
134 
135   testScanf("%10s", 1, 11);
136   testScanf("%10c", 1, 10);
137   testScanf("%10ls", 1, 11 * LC);
138   testScanf("%10lc", 1, 10 * LC);
139   testScanf("%%10s", 0);
140   testScanf("%*10s", 0);
141   testScanf("%*d", 0);
142 
143   testScanf("%4d%8f%c", 3, I, F, C);
144   testScanf("%s%d", 2, test_buf_size, I);
145   testScanf("%[abc]", 1, test_buf_size);
146   testScanf("%4[bcdef]", 1, 5);
147   testScanf("%[]]", 1, test_buf_size);
148   testScanf("%8[^]%d0-9-]%c", 2, 9, C);
149 
150   testScanf("%*[^:]%n:%d:%1[ ]%n", 4, I, I, 2, I);
151 
152   testScanf("%*d%u", 1, I);
153 
154   testScanf("%c%d", 2, C, I);
155   testScanf("%A%lf", 2, F, D);
156 
157   testScanf("s%Las", 1, LD);
158   testScanf("%ar", 1, F);
159 
160   // In the cases with std::min below the format spec can be interpreted as
161   // either floating-something, or (GNU extension) callee-allocated string.
162   // Our conservative implementation reports one of the two possibilities with
163   // the least store range.
164   testScanf("%a[", 0);
165   testScanf("%a[]", 0);
166   testScanf("%a[]]", 1, std::min(F, P));
167   testScanf("%a[abc]", 1, std::min(F, P));
168   testScanf("%a[^abc]", 1, std::min(F, P));
169   testScanf("%a[ab%c] %d", 0);
170   testScanf("%a[^ab%c] %d", 0);
171   testScanf("%as", 1, std::min(F, P));
172   testScanf("%aS", 1, std::min(F, P));
173   testScanf("%a13S", 1, std::min(F, P));
174   testScanf("%alS", 1, std::min(F, P));
175 
176   testScanfNoGnuMalloc("s%Las", 1, LD);
177   testScanfNoGnuMalloc("%ar", 1, F);
178   testScanfNoGnuMalloc("%a[", 1, F);
179   testScanfNoGnuMalloc("%a[]", 1, F);
180   testScanfNoGnuMalloc("%a[]]", 1, F);
181   testScanfNoGnuMalloc("%a[abc]", 1, F);
182   testScanfNoGnuMalloc("%a[^abc]", 1, F);
183   testScanfNoGnuMalloc("%a[ab%c] %d", 3, F, C, I);
184   testScanfNoGnuMalloc("%a[^ab%c] %d", 3, F, C, I);
185   testScanfNoGnuMalloc("%as", 1, F);
186   testScanfNoGnuMalloc("%aS", 1, F);
187   testScanfNoGnuMalloc("%a13S", 1, F);
188   testScanfNoGnuMalloc("%alS", 1, F);
189 
190   testScanf("%5$d", 0);
191   testScanf("%md", 0);
192   testScanf("%m10s", 0);
193 
194   testScanfPartial("%d%d%d%d //1\n", 1, 1, I);
195   testScanfPartial("%d%d%d%d //2\n", 2, 2, I, I);
196   testScanfPartial("%d%d%d%d //3\n", 3, 3, I, I, I);
197   testScanfPartial("%d%d%d%d //4\n", 4, 4, I, I, I, I);
198 
199   testScanfPartial("%d%n%n%d //1\n", 1, 3, I, I, I);
200   testScanfPartial("%d%n%n%d //2\n", 2, 4, I, I, I, I);
201 
202   testScanfPartial("%d%n%n%d %s %s", 3, 5, I, I, I, I, test_buf_size);
203   testScanfPartial("%d%n%n%d %s %s", 4, 6, I, I, I, I, test_buf_size,
204                    test_buf_size);
205 }
206 
TEST(SanitizerCommonInterceptors,ScanfAllocate)207 TEST(SanitizerCommonInterceptors, ScanfAllocate) {
208   const char *buf = "123456";
209 
210   // Can not use testScanf() because this case needs a valid pointer to a string
211   // in the scanf argument.
212   {
213     std::vector<unsigned> scanf_sizes;
214     testScanf3((void *)&scanf_sizes, 2, /*allowGnuMalloc=*/false, "%ms", &buf);
215     verifyFormatResults("%ms", 2, scanf_sizes,
216                         {P, (unsigned)(strlen(buf) + 1)});
217   }
218 
219   {
220     std::vector<unsigned> scanf_sizes;
221     testScanf3((void *)&scanf_sizes, 2, /*allowGnuMalloc=*/false, "%mc", &buf);
222     verifyFormatResults("%mc", 2, scanf_sizes,
223                         {P, (unsigned)(strlen(buf) + 1)});
224   }
225 }
226 
testPrintf3(void * ctx,const char * format,...)227 static void testPrintf3(void *ctx, const char *format, ...) {
228   va_list ap;
229   va_start(ap, format);
230   printf_common(ctx, format, ap);
231   va_end(ap);
232 }
233 
testPrintf2(const char * format,unsigned n,va_list expected_sizes_va)234 static void testPrintf2(const char *format, unsigned n,
235                         va_list expected_sizes_va) {
236   std::vector<unsigned> printf_sizes, expected_sizes;
237   for (unsigned i = 0; i < n; ++i)
238     expected_sizes.push_back(va_arg(expected_sizes_va, unsigned));
239 
240   // 16 args should be enough.
241   testPrintf3((void *)&printf_sizes, format,
242              test_buf, test_buf, test_buf, test_buf, test_buf, test_buf,
243              test_buf, test_buf, test_buf, test_buf, test_buf, test_buf,
244              test_buf, test_buf, test_buf, test_buf);
245   verifyFormatResults(format, n, printf_sizes, expected_sizes);
246 }
247 
testPrintf(const char * format,unsigned n,...)248 static void testPrintf(const char *format, unsigned n, ...) {
249   va_list ap;
250   va_start(ap, n);
251   testPrintf2(format, n, ap);
252   va_end(ap);
253 }
254 
TEST(SanitizerCommonInterceptors,Printf)255 TEST(SanitizerCommonInterceptors, Printf) {
256   // Only test functionality which differs from scanf
257 
258   // Indexed arguments
259   testPrintf("%5$d", 0);
260   testPrintf("%.*5$d", 0);
261 
262   // errno
263   testPrintf("%0-m", 0);
264 
265   // Dynamic width
266   testPrintf("%*n", 1, I);
267   testPrintf("%*.10n", 1, I);
268 
269   // Precision
270   testPrintf("%10.10n", 1, I);
271   testPrintf("%.3s", 1, 3);
272   testPrintf("%.20s", 1, test_buf_size);
273 
274   // Dynamic precision
275   testPrintf("%.*n", 1, I);
276   testPrintf("%10.*n", 1, I);
277 
278   // Dynamic precision for strings is not implemented yet.
279   testPrintf("%.*s", 1, 0);
280 
281   // Checks for wide-character strings are not implemented yet.
282   testPrintf("%ls", 1, 0);
283 
284   testPrintf("%m", 0);
285   testPrintf("%m%s", 1, test_buf_size);
286   testPrintf("%s%m%s", 2, test_buf_size, test_buf_size);
287 }
288