Hi,

On Sun, Aug 29, 2021 at 09:38:37AM -0700, Joe Perches wrote:

On Sun, 2021-08-29 at 18:15 +0200, Len Baker wrote:

quoted

strcpy() performs no bounds checking on the destination buffer. This
could result in linear overflows beyond the end of the buffer, leading
to all kinds of misbehaviors. The safe replacement is strscpy() [1].

However, to simplify and clarify the code, to concatenate labels use
the scnprintf() function. This way it is not necessary to check the
return value of strscpy (-E2BIG if the parameter count is 0 or the src
was truncated) since the scnprintf returns always the number of chars
written into the buffer. This function returns always a nul-terminated
string even if it needs to be truncated.

[]

quoted

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c

[]

quoted

@@ -1113,12 +1116,11 @@ void edac_mc_handle_error(const enum hw_event_mc_err_type type,

 			p = e->label;
 			*p = '\0';
 		} else {
-			if (p != e->label) {
-				strcpy(p, OTHER_LABEL);
-				p += strlen(OTHER_LABEL);
-			}
-			strcpy(p, dimm->label);
-			p += strlen(p);
+			const char *or = (p != e->label) ? OTHER_LABEL : "";
+
+			n = scnprintf(p, len, "%s%s", or, dimm->label);
+			len -= n;
+			p += n;

A very common and intelligible mechanism for this is:

	const char *prefix = "";
	int n = 0;
	...
			n += scnprintf(e->label + n, sizeof(e->label) - n,
				       "%s%s", prefix, dimm->label);
			prefix = " or ";

Ok, I will send a new version using this common mechanism. Thanks for the
advise.

Regards,
Len