Args.c: add missing length check

uli42 · uli42 · commit 706136c01dcb · 2017-11-21T00:45:49.000+01:00
Will currently not trigger because the length of the md5 is way shorter
than nxagentDialogName, but it will become a problem if those sizes
ever change, e.g. a new hash function is used.
diff --git a/nx-X11/programs/Xserver/hw/nxagent/Args.c b/nx-X11/programs/Xserver/hw/nxagent/Args.c
@@ -2005,7 +2005,8 @@ static int nxagentGetDialogName()
 
     if (length > 0 && nxagentSessionId[length] == '-')
     {
-      strncat(nxagentDialogName, nxagentSessionId, length));
+      strncat(nxagentDialogName, nxagentSessionId,
+              MIN(length, sizeof(nxagentDialogName) - 1 - strlen(prefix)));
     }
     else
     {

Original file line number	Diff line number	Diff line change
`@@ -2005,7 +2005,8 @@ static int nxagentGetDialogName()`
`2005`	`2005`
`2006`	`2006`	`if (length > 0 && nxagentSessionId[length] == '-')`
`2007`	`2007`	`{`
`2008`		`- strncat(nxagentDialogName, nxagentSessionId, length));`
	`2008`	`+ strncat(nxagentDialogName, nxagentSessionId,`
	`2009`	`+ MIN(length, sizeof(nxagentDialogName) - 1 - strlen(prefix)));`
`2009`	`2010`	`}`
`2010`	`2011`	`else`
`2011`	`2012`	`{`