From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:41366 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728309AbfL0SQN (ORCPT ); Fri, 27 Dec 2019 13:16:13 -0500 From: Sasha Levin Subject: [PATCH AUTOSEL 4.4 19/25] kconfig: don't crash on NULL expressions in expr_eq() Date: Fri, 27 Dec 2019 13:15:43 -0500 Message-Id: <20191227181549.8040-19-sashal@kernel.org> In-Reply-To: <20191227181549.8040-1-sashal@kernel.org> References: <20191227181549.8040-1-sashal@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Hebb , Masahiro Yamada , Sasha Levin , linux-kbuild@vger.kernel.org From: Thomas Hebb [ Upstream commit 272a72103012862e3a24ea06635253ead0b6e808 ] NULL expressions are taken to always be true, as implemented by the expr_is_yes() macro and by several other functions in expr.c. As such, they ought to be valid inputs to expr_eq(), which compares two expressions. Signed-off-by: Thomas Hebb Signed-off-by: Masahiro Yamada Signed-off-by: Sasha Levin --- scripts/kconfig/expr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c index ed29bad1f03a..96420b620963 100644 --- a/scripts/kconfig/expr.c +++ b/scripts/kconfig/expr.c @@ -201,6 +201,13 @@ static int expr_eq(struct expr *e1, struct expr *e2) { int res, old_count; + /* + * A NULL expr is taken to be yes, but there's also a different way to + * represent yes. expr_is_yes() checks for either representation. + */ + if (!e1 || !e2) + return expr_is_yes(e1) && expr_is_yes(e2); + if (e1->type != e2->type) return 0; switch (e1->type) { -- 2.20.1