================ @@ -938,6 +938,53 @@ optin.portability.UnixAPI """"""""""""""""""""""""" Finds implementation-defined behavior in UNIX/Posix functions. +.. _optin-taint-TaintAlloc: + +optin.taint.TaintAlloc (C, C++) +""""""""""""""""""""""""""""""" + +This checker warns for cases when the ``size`` parameter of the ``malloc`` , +``calloc``, ``realloc``, ``alloca`` or the size parameter of the +array new C++ operator is tainted (potentially attacker controlled). +If an attacker can inject a large value as the size parameter, memory exhaustion +denial of service attack can be carried out. + +The ``alpha.security.taint.TaintPropagation`` checker also needs to be enabled for +this checker to give warnings. + +The analyzer emits warning only if it cannot prove that the size parameter is +within reasonable bounds (``<= SIZE_MAX/4``). This functionality partially +covers the SEI Cert coding standard rule `INT04-C +<https://wiki.sei.cmu.edu/confluence/display/c/INT04-C.+Enforce+limits+on+integer+values+originating+from+tainted+sources>`_. + +You can silence this warning either by bound checking the ``size`` parameter, or +by explicitly marking the ``size`` parameter as sanitized. See the +:ref:`alpha-security-taint-TaintPropagation` checker for more details. + +.. code-block:: c + + void t1(void) { + size_t size; + scanf("%zu", &size); + int *p = malloc(size); // warn: malloc is called with a tainted (potentially attacker controlled) value + free(p); + } + + void t3(void) { ---------------- NagyDonat wrote:
```suggestion void bounds_checked(void) { ``` https://github.com/llvm/llvm-project/pull/92420 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits