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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C14FC6377D for ; Thu, 22 Jul 2021 06:07:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E91A6127C for ; Thu, 22 Jul 2021 06:07:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230286AbhGVF0j (ORCPT ); Thu, 22 Jul 2021 01:26:39 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:12285 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229967AbhGVF0h (ORCPT ); Thu, 22 Jul 2021 01:26:37 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4GVhgX4YFVz7vf1; Thu, 22 Jul 2021 14:02:32 +0800 (CST) Received: from dggpemm500016.china.huawei.com (7.185.36.25) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Thu, 22 Jul 2021 14:07:09 +0800 Received: from DESKTOP-2MIM39K.china.huawei.com (10.67.101.83) by dggpemm500016.china.huawei.com (7.185.36.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Thu, 22 Jul 2021 14:07:09 +0800 From: Yuchen Wei To: , CC: , , , , , , Subject: [PATCH] arm64: audit: fix return value high 32bit truncation problem Date: Thu, 22 Jul 2021 14:07:07 +0800 Message-ID: <20210722060707.531-1-weiyuchen3@huawei.com> X-Mailer: git-send-email 2.31.1.windows.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.67.101.83] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500016.china.huawei.com (7.185.36.25) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: weiyuchen Add error code judgment in invoke_syscall() to prevent kernel components such as audit and tracepoint from obtaining incorrect return values. For example: type=SYSCALL msg=audit(342.780:69): arch=40000028 syscall=235 success=yes exit=4294967235 The syscall return value is -61, but due to the following process in invoke_syscall(): if (is_compat_task()) ret = lower_32_bits(ret); regs->regs[0] = ret; The return value audit or tracepoint get from regs[0] is 4294967235, which is an incorrect return value. Signed-off-by: weiyuchen --- arch/arm64/kernel/syscall.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index 263d6c1a525f..f9f042d9a088 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -54,7 +54,7 @@ static void invoke_syscall(struct pt_regs *regs, unsigned int scno, ret = do_ni_syscall(regs, scno); } - if (is_compat_task()) + if (is_compat_task() && !IS_ERR_VALUE(ret)) ret = lower_32_bits(ret); regs->regs[0] = ret; -- 2.12.3