scripts/kallsyms: fix memory corruption caused by write over-run

memcpy() writes one more byte than allocated.

Fixes: 8d60526999aa ("scripts/kallsyms: change table to store (strcut sym_entry *)")
Reported-by: youling257 <youling257@gmail.com>
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Pavel Machek <pavel@ucw.cz>
diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index a566d82..0133dfa 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -210,7 +210,7 @@
 
 	len = strlen(name) + 1;
 
-	sym = malloc(sizeof(*sym) + len);
+	sym = malloc(sizeof(*sym) + len + 1);
 	if (!sym) {
 		fprintf(stderr, "kallsyms failure: "
 			"unable to allocate required amount of memory\n");
@@ -219,7 +219,7 @@
 	sym->addr = addr;
 	sym->len = len;
 	sym->sym[0] = type;
-	memcpy(sym_name(sym), name, len);
+	strcpy(sym_name(sym), name);
 	sym->percpu_absolute = 0;
 
 	return sym;