PR23230 Fix asan strtol_strict/strtoll_strict tests

[m.guseva]

Summary

This is a patch to fix the bug reported here: https://llvm.org/bugs/show_bug.cgi?id=23230

[kcc]

test/asan/TestCases/strtol_strict.c

45

ouch. This is going to corrupt asan's heap internals and may cause other kinds of flakiness in the test.
I would suggest to allocate a larger buffer, write 0 to the first 8 bytes, apply __asan_poison_memory to those first 8 bytes,
and then pass pass the address to one of those 8 bytes to strtol.
This way you will get a reliable test.

[m.guseva]

Kostya, thank you.
Attached new patch. What do you think?

[kcc]

LGTM

[kcc]

LGTM

test/asan/TestCases/strtol_strict.c

 void test2(char *array, char *endptr) {
   // Buffer overflow if there is no terminating null (depends on base)
   array[2] = 'z';
   long r = strtol(array, &endptr, 35);
   assert(array + 2 == endptr);
   assert(r == 37);
 }
 
+void __attribute__((no_sanitize_address)) underflow_write(char *array) {
+  array[-1] = '\0';
+}
+
 void test3(char *array, char *endptr) {
+  underflow_write(array);
   // Buffer overflow if base is invalid.
   long r = strtol(array - 1, NULL, -1);
   assert(r == 0);
 }
 
 void test4(char *array, char *endptr) {
   // Buffer overflow if base is invalid.
   long r = strtol(array + 3, NULL, 1);
int main(int argc, char **argv) {
   if (!strcmp(argv[1], "test1")) test1(array, endptr);
   // CHECK1: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK1: READ of size 4
   if (!strcmp(argv[1], "test2")) test2(array, endptr);
   // CHECK2: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK2: READ of size 4
   if (!strcmp(argv[1], "test3")) test3(array, endptr);
   // CHECK3: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
-  // CHECK3: READ of size 5
+  // CHECK3: READ of size 1
   if (!strcmp(argv[1], "test4")) test4(array, endptr);
   // CHECK4: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK4: READ of size 1
   if (!strcmp(argv[1], "test5")) test5(array, endptr);
   // CHECK5: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK5: READ of size 4
   if (!strcmp(argv[1], "test6")) test6(array, endptr);
   // CHECK6: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK6: READ of size 4
   if (!strcmp(argv[1], "test7")) test7(array, endptr);
   // CHECK7: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK7: READ of size 2
   free(array);
   return 0;
 }

test/asan/TestCases/strtoll_strict.c

 void test2(char *array, char *endptr) {
   // Buffer overflow if there is no terminating null (depends on base)
   array[2] = 'z';
   long long r = strtoll(array, &endptr, 35);
   assert(array + 2 == endptr);
   assert(r == 37);
 }
 
+void __attribute__((no_sanitize_address)) underflow_write(char *array) {
+  array[-1] = '\0';
+}
+
 void test3(char *array, char *endptr) {
+  underflow_write(array);
   // Buffer overflow if base is invalid.
   long long r = strtoll(array - 1, NULL, -1);
   assert(r == 0);
 }
 
 void test4(char *array, char *endptr) {
   // Buffer overflow if base is invalid.
   long long r = strtoll(array + 3, NULL, 1);
int main(int argc, char **argv) {
   if (!strcmp(argv[1], "test1")) test1(array, endptr);
   // CHECK1: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK1: READ of size 4
   if (!strcmp(argv[1], "test2")) test2(array, endptr);
   // CHECK2: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK2: READ of size 4
   if (!strcmp(argv[1], "test3")) test3(array, endptr);
   // CHECK3: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
-  // CHECK3: READ of size 5
+  // CHECK3: READ of size 1
   if (!strcmp(argv[1], "test4")) test4(array, endptr);
   // CHECK4: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK4: READ of size 1
   if (!strcmp(argv[1], "test5")) test5(array, endptr);
   // CHECK5: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK5: READ of size 4
   if (!strcmp(argv[1], "test6")) test6(array, endptr);
   // CHECK6: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK6: READ of size 4
   if (!strcmp(argv[1], "test7")) test7(array, endptr);
   // CHECK7: {{.*ERROR: AddressSanitizer: heap-buffer-overflow on address}}
   // CHECK7: READ of size 2
   free(array);
   return 0;
 }