Fix UB in v4raw_ref::operator==

kovdan01 · kovdan01 · commit 90677eb58ca1 · 2021-05-09T15:43:14.000+03:00
Behaviour of memcmp is undefined if any of pointers passed to it is null. See https://en.cppreference.com/w/c/string/byte/memcmp for details. UB was detected on test MSGPACK_V4RAW_REF.pack_unpack_fix_l with UB-sanitizer.
diff --git a/include/msgpack/v1/adaptor/v4raw.hpp b/include/msgpack/v1/adaptor/v4raw.hpp
@@ -33,7 +33,7 @@ struct v4raw_ref {
 
     bool operator== (const v4raw_ref& x) const
     {
-        return size == x.size && std::memcmp(ptr, x.ptr, size) == 0;
+        return size == x.size && (size == 0 || std::memcmp(ptr, x.ptr, size) == 0);
     }
 
     bool operator!= (const v4raw_ref& x) const

Original file line number	Diff line number	Diff line change
`@@ -33,7 +33,7 @@ struct v4raw_ref {`
`33`	`33`
`34`	`34`	`bool operator== (const v4raw_ref& x) const`
`35`	`35`	`{`
`36`		`- return size == x.size && std::memcmp(ptr, x.ptr, size) == 0;`
	`36`	`+ return size == x.size && (size == 0 \|\| std::memcmp(ptr, x.ptr, size) == 0);`
`37`	`37`	`}`
`38`	`38`
`39`	`39`	`bool operator!= (const v4raw_ref& x) const`