Use /dev/urandom instead of /dev/null for probing valid memory (#1586)

tokatoka · web-flow · commit b20fda2a4ada · 2023-10-01T23:08:29.000-05:00
diff --git a/libafl_targets/src/cmplog.c b/libafl_targets/src/cmplog.c
@@ -60,7 +60,7 @@ static long area_is_valid(const void *ptr, size_t len) {
   valid_len = (long)len;
 #elif defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
   if (!dymmy_initialized) {
-    if ((dummy_fd[1] = open("/dev/null", O_WRONLY)) < 0) {
+    if ((dummy_fd[1] = open("/dev/urandom", O_WRONLY)) < 0) {
       if (pipe(dummy_fd) < 0) { dummy_fd[1] = 1; }
     }
     dymmy_initialized = 1;

Original file line number	Diff line number	Diff line change
`@@ -60,7 +60,7 @@ static long area_is_valid(const void *ptr, size_t len) {`
`60`	`60`	`valid_len = (long)len;`
`61`	`61`	`#elif defined(__unix__) \|\| (defined(__APPLE__) && defined(__MACH__))`
`62`	`62`	`if (!dymmy_initialized) {`
`63`		`- if ((dummy_fd[1] = open("/dev/null", O_WRONLY)) < 0) {`
	`63`	`+ if ((dummy_fd[1] = open("/dev/urandom", O_WRONLY)) < 0) {`
`64`	`64`	`if (pipe(dummy_fd) < 0) { dummy_fd[1] = 1; }`
`65`	`65`	`}`
`66`	`66`	`dymmy_initialized = 1;`