strparser: Fix sign of err codes

strp_parser_err is called with a negative code everywhere, which then
calls abort_parser with a negative code.  strp_msg_timeout calls
abort_parser directly with a positive code.  Negate ETIMEDOUT
to match signed-ness of other calls.

The default abort_parser callback, strp_abort_strp, sets
sk->sk_err to err.  Also negate the error here so sk_err always
holds a positive value, as the rest of the net code expects.  Currently
a negative sk_err can result in endless loops, or user code that
thinks it actually sent/received err bytes.

Found while testing net/tls_sw recv path.

Fixes: 43a0c675 ("strparser: Stream parser for messages")
Signed-off-by: Dave Watson <davejwatson@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/strparser/strparser.c

@@ -60,7 +60,7 @@ static void strp_abort_strp(struct strparser *strp, int err)
 		struct sock *sk = strp->sk;
 
 		/* Report an error on the lower socket */
-		sk->sk_err = err;
+		sk->sk_err = -err;
 		sk->sk_error_report(sk);
 	}
 }
@@ -458,7 +458,7 @@ static void strp_msg_timeout(struct work_struct *w)
 	/* Message assembly timed out */
 	STRP_STATS_INCR(strp->stats.msg_timeouts);
 	strp->cb.lock(strp);
-	strp->cb.abort_parser(strp, ETIMEDOUT);
+	strp->cb.abort_parser(strp, -ETIMEDOUT);
 	strp->cb.unlock(strp);
 }