Add XNFcallocarray() to allow xnfcalloc() to check for overflow

The xnfcalloc() macro took two arguments but simply multiplied them
together without checking for overflow and defeating any overflow
checking that calloc() might have done.  Let's not do that.

The original XNFcalloc() function is left for now to preserve driver
ABI, but is marked as deprecated so it can be removed in a future round
of ABI break/cleanup.

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/os/utils.c b/os/utils.c
index 75769f17c..24a87516e 100644
--- a/os/utils.c
+++ b/os/utils.c
@@ -1128,10 +1128,20 @@ XNFalloc(unsigned long amount)
     return ptr;
 }
 
+/* The original XNFcalloc was used with the xnfcalloc macro which multiplied
+ * the arguments at the call site without allowing calloc to check for overflow.
+ * XNFcallocarray was added to fix that without breaking ABI.
+ */
 void *
 XNFcalloc(unsigned long amount)
 {
-    void *ret = calloc(1, amount);
+    return XNFcallocarray(1, amount);
+}
+
+void *
+XNFcallocarray(size_t nmemb, size_t size)
+{
+    void *ret = calloc(nmemb, size);
 
     if (!ret)
         FatalError("XNFcalloc: Out of memory");