rxrpc: Fix checker warning

jira LE-1907
Rebuild_History Non-Buildable kernel-5.14.0-284.30.1.el9_2
commit-author David Howells <[email protected]>
commit 84924aa

Fix the following checker warning:

../net/rxrpc/key.c:692:9: error: subtraction of different types can't work (different address spaces)

Checker is wrong in this case, but cast the pointers to unsigned long to
avoid the warning.

Whilst we're at it, reduce the assertions to WARN_ON() and return an error.

	Signed-off-by: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
(cherry picked from commit 84924aa)
	Signed-off-by: Jonathan Maple <[email protected]>

Author: PlaidCat

net/rxrpc/key.c

@@ -602,7 +602,8 @@ static long rxrpc_read(const struct key *key,
 		}
 
 		_debug("token[%u]: toksize=%u", ntoks, toksize);
-		ASSERTCMP(toksize, <=, AFSTOKEN_LENGTH_MAX);
+		if (WARN_ON(toksize > AFSTOKEN_LENGTH_MAX))
+			return -EIO;
 
 		toksizes[ntoks++] = toksize;
 		size += toksize + 4; /* each token has a length word */
@@ -679,17 +680,20 @@ static long rxrpc_read(const struct key *key,
 			return -ENOPKG;
 		}
 
-		ASSERTCMP((unsigned long)xdr - (unsigned long)oldxdr, ==,
-			  toksize);
+		if (WARN_ON((unsigned long)xdr - (unsigned long)oldxdr ==
+			    toksize))
+			return -EIO;
 	}
 
 #undef ENCODE_STR
 #undef ENCODE_DATA
 #undef ENCODE64
 #undef ENCODE
 
-	ASSERTCMP(tok, ==, ntoks);
-	ASSERTCMP((char __user *) xdr - buffer, ==, size);
+	if (WARN_ON(tok != ntoks))
+		return -EIO;
+	if (WARN_ON((unsigned long)xdr - (unsigned long)buffer != size))
+		return -EIO;
 	_leave(" = %zu", size);
 	return size;
 }