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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 DBA44C43463 for ; Fri, 18 Sep 2020 02:23:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F30122211 for ; Fri, 18 Sep 2020 02:23:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600395791; bh=7Xh9F1ci2528vKTY1xThQGNGytWsAB3Od7yBhA/c6bY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gpeI2vqxm8lgccL2KY1z8/sKosn+O7Yq0M+m7Ms+7ZzuE9Z3vfT+J4usXUsz6fdzk W4MR4kSzmxA7o19hAXfp3kBZlxQ75KoCQG6DtwvdV9DK/iAp6K3GxHkuCz+lcw3nAn 4T8W5un3hdIfFdVhjpM8Zwhhfe76BSqmGRfaE4dY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729161AbgIRCXK (ORCPT ); Thu, 17 Sep 2020 22:23:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:47172 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729472AbgIRCQ6 (ORCPT ); Thu, 17 Sep 2020 22:16:58 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2104A2395B; Fri, 18 Sep 2020 02:16:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600395418; bh=7Xh9F1ci2528vKTY1xThQGNGytWsAB3Od7yBhA/c6bY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=s53jiCzF1RDL5BI/nZn0pvrl66t+Rbc8WxaM65xAQ5h4wJG0zlEtmw7C95n17qUlU Qtibizsgnc5HvBlAN/tVbdZvuvgbGnsQ4HmePRIhTLoWq8rwqNGLl/Xrdt3GG/Yk6K W7reVTeZbXYNJs7empwSYIXazK2dGZU3b6DQ3zcU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Joe Perches , Dan Carpenter , Julia Lawall , Thomas Gleixner , Kees Cook , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL 4.4 12/64] kernel/sys.c: avoid copying possible padding bytes in copy_to_user Date: Thu, 17 Sep 2020 22:15:51 -0400 Message-Id: <20200918021643.2067895-12-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200918021643.2067895-1-sashal@kernel.org> References: <20200918021643.2067895-1-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: Joe Perches [ Upstream commit 5e1aada08cd19ea652b2d32a250501d09b02ff2e ] Initialization is not guaranteed to zero padding bytes so use an explicit memset instead to avoid leaking any kernel content in any possible padding bytes. Link: http://lkml.kernel.org/r/dfa331c00881d61c8ee51577a082d8bebd61805c.camel@perches.com Signed-off-by: Joe Perches Cc: Dan Carpenter Cc: Julia Lawall Cc: Thomas Gleixner Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- kernel/sys.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sys.c b/kernel/sys.c index 1855f1bf113e4..e98664039cb23 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1183,11 +1183,13 @@ SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) { - struct oldold_utsname tmp = {}; + struct oldold_utsname tmp; if (!name) return -EFAULT; + memset(&tmp, 0, sizeof(tmp)); + down_read(&uts_sem); memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); -- 2.25.1