stack smashing

README.adoc

@@ -13096,6 +13096,16 @@ The following sections are related to multithreading in userland:
 ** <<number-of-cores-in-qemu-user-mode>>
 ** <<number-of-cores-in-gem5-user-mode>>
 
+=== C debugging
+
+Let's group the hard-to-debug undefined-behaviour-like stuff found in C / C+ here and how to tackle those problems.
+
+==== Stack smashing
+
+https://stackoverflow.com/questions/1345670/stack-smashing-detected/51897264#51897264
+
+link:userland/c/smash_stack.c[]
+
 === Userland content bibliography
 
 * The Linux Programming Interface by Michael Kerrisk https://www.amazon.co.uk/Linux-Programming-Interface-System-Handbook/dp/1593272200 Lots of open source POSIX examples: https://github.com/cirosantilli/linux-programming-interface-kerrisk

path_properties.py

@@ -480,6 +480,9 @@ path_properties_tuples = (
                         'assert_fail.c': {
                             'signal_received': signal.Signals.SIGABRT,
                         },
+                        'smash_stack.c': {
+                            'skip_run_unclassified': True,
+                        },
                         'exit1.c': {'exit_status': 1},
                         'exit2.c': {'exit_status': 2},
                         'false.c': {'exit_status': 1},

userland/c/smash_stack.c

@@ -0,0 +1,17 @@
+/* https://cirosantilli.com/linux-kernel-module-cheat#stack-smashing */
+
+void myfunc(char *const src, int len) {
+    int i;
+    for (i = 0; i < len; ++i) {
+        src[i] = 42;
+    }
+}
+
+int main(void) {
+    char arr[] = {'a', 'b', 'c', 'd'};
+    int len = sizeof(arr);
+    myfunc(arr, len);
+    myfunc(arr, len + 1);
+    myfunc(arr, len);
+    return 0;
+}