From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9BE0C433F5 for ; Wed, 30 Mar 2022 11:50:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344133AbiC3Lvu (ORCPT ); Wed, 30 Mar 2022 07:51:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344105AbiC3Lu7 (ORCPT ); Wed, 30 Mar 2022 07:50:59 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D4272706F7; Wed, 30 Mar 2022 04:47:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E09A7615F5; Wed, 30 Mar 2022 11:47:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA985C3410F; Wed, 30 Mar 2022 11:47:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648640872; bh=B+LL6HqRHaXg/j5A4/f7HpsysJBncMEphF9/Mdw/N7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KA9MBMx9ycrp+J1LNOnriRa1Ftta4cFb5mjmXy/vmUDqEEIzvXkwc1Cyg/M2HNEoX 8OCVONV4yBqBaXqOnIU2oTa3FYYvzDDSPxZ6pdNOzdWklre4MtnBxFpVX80XKy3OWN 3pxh6r3zMPN/2cRhaTek2qmv/6FyzgGlxBA6CcURkFXXBzrd9ju4H0jbRA31CdU4qP oF+UbjqKruZYTJ2ATNZEJdcR3XPM9Vs697oq13Cfc3JzrjHWJk64qOq2tkdNfrVVTw K15mnwOdhtn8NS3U2AoFBCnwilsazTm/j8pj748KmDr5VK8KQk6f8jUq+5kXiylIih sdMGRY3ANkHAw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arnd Bergmann , Sasha Levin Subject: [PATCH AUTOSEL 5.17 42/66] lib/test_lockup: fix kernel pointer check for separate address spaces Date: Wed, 30 Mar 2022 07:46:21 -0400 Message-Id: <20220330114646.1669334-42-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220330114646.1669334-1-sashal@kernel.org> References: <20220330114646.1669334-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann [ Upstream commit 5a06fcb15b43d1f7bf740c672950122331cb5655 ] test_kernel_ptr() uses access_ok() to figure out if a given address points to user space instead of kernel space. However on architectures that set CONFIG_ALTERNATE_USER_ADDRESS_SPACE, a pointer can be valid for both, and the check always fails because access_ok() returns true. Make the check for user space pointers conditional on the type of address space layout. Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin --- lib/test_lockup.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/lib/test_lockup.c b/lib/test_lockup.c index 6a0f329a794a..c3fd87d6c2dd 100644 --- a/lib/test_lockup.c +++ b/lib/test_lockup.c @@ -417,9 +417,14 @@ static bool test_kernel_ptr(unsigned long addr, int size) return false; /* should be at least readable kernel address */ - if (access_ok((void __user *)ptr, 1) || - access_ok((void __user *)ptr + size - 1, 1) || - get_kernel_nofault(buf, ptr) || + if (!IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE) && + (access_ok((void __user *)ptr, 1) || + access_ok((void __user *)ptr + size - 1, 1))) { + pr_err("user space ptr invalid in kernel: %#lx\n", addr); + return true; + } + + if (get_kernel_nofault(buf, ptr) || get_kernel_nofault(buf, ptr + size - 1)) { pr_err("invalid kernel ptr: %#lx\n", addr); return true; -- 2.34.1