From patchwork Tue May 30 16:40:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Azeem Shaikh X-Patchwork-Id: 13260764 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 8CE45C77B73 for ; Tue, 30 May 2023 16:40:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231404AbjE3QkL (ORCPT ); Tue, 30 May 2023 12:40:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233194AbjE3QkK (ORCPT ); Tue, 30 May 2023 12:40:10 -0400 Received: from mail-io1-xd2f.google.com (mail-io1-xd2f.google.com [IPv6:2607:f8b0:4864:20::d2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4D258F; Tue, 30 May 2023 09:40:09 -0700 (PDT) Received: by mail-io1-xd2f.google.com with SMTP id ca18e2360f4ac-7773a735bf8so46703339f.1; Tue, 30 May 2023 09:40:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1685464809; x=1688056809; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=y9agsz9BdjIrnVIxMaWFsK/cg3sewH3cif2PKAjY54I=; b=A4n+XhPujTRI+NiRmDmvoi3Hoq6SkXjqZHO7TUcoOpafJPQqCKiZSaZkESe4mrOBDo pdla6Kmb1acTOmDCpBKITbAbdjuXF/ZQ9OSn1yrD6ExSuADNkkHVefu2zMfCepFibH/y X/GD3wN5lTeNDOVKW2oXNOZcnMvXte5ZQtzkiDqeMiL4PHyUNC8piFNmGzzmZ6yZ//Do GZTsTNdhEcsuudsZR7zyiE23IHQKzf2+7xFujVaD+7XM0n3LyEGSiocbVsXbN4WMeyP+ 3lesFI3FS6EF1VMM3Oj2fhmjD8Xb2k9TJNjomesUswmn8T0pBs7UfsOpyVeobKPY8d1y bO9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685464809; x=1688056809; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=y9agsz9BdjIrnVIxMaWFsK/cg3sewH3cif2PKAjY54I=; b=TiWziHXNnXLcMVIiRBXKRv0a9096yl1wueABlPTp5m4Q80AY7UFUIvPqblJGK1aZ/U ZAoornR5JSrherRu45Kuie+U6+VhOcMtX7cSKCUftML4i3KP7DU11SW3K1SVe84E/jPP XwPJlhK+3utwePUDFcOrIxUSPB18ibQ0O1UX6XHCO6Fz13sMO/tzIAgHl5A4aYc7gx2Q yyOq1YvlQEvj0YXKKlAmCeUMBprbWjO6nFfR+qXyO643HX7pU4o789c7SHgaPIpUHwGt zkfoI79i9jCFvnmh2YsfYfnbE1iJm/x+WNjTnbTumS3fb3QanADtOyH+kQST2M6JsiJh 7n0g== X-Gm-Message-State: AC+VfDwEsfoBFF7kLhkR3dAKuo/wwGFDJXhEc/fFOqlm7RV8XeBLTpzY vfKZuU6JRX/cT4DqfJqw+tk= X-Google-Smtp-Source: ACHHUZ5MI/JShx0lc4b7BjKuSUS7T9wjVGEPE6GI2tCvjroHoHLFi6oGYoUUd77mQWSytwYcuyvKkA== X-Received: by 2002:a05:6602:2598:b0:760:ed78:a252 with SMTP id p24-20020a056602259800b00760ed78a252mr2054989ioo.9.1685464808981; Tue, 30 May 2023 09:40:08 -0700 (PDT) Received: from azeems-kspp.c.googlers.com.com (54.70.188.35.bc.googleusercontent.com. [35.188.70.54]) by smtp.gmail.com with ESMTPSA id l13-20020a6b700d000000b0076c81bf2731sm3330165ioc.20.2023.05.30.09.40.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 May 2023 09:40:08 -0700 (PDT) From: Azeem Shaikh To: Maxim Krasnyansky Cc: linux-hardening@vger.kernel.org, Azeem Shaikh , linux-kernel@vger.kernel.org, Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org Subject: [PATCH] uml: Replace all non-returning strlcpy with strscpy Date: Tue, 30 May 2023 16:40:04 +0000 Message-ID: <20230530164004.986750-1-azeemshaikh38@gmail.com> X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh Reviewed-by: Kees Cook --- arch/um/os-Linux/drivers/tuntap_user.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c index 53eb3d508645..2284e9c1cbbb 100644 --- a/arch/um/os-Linux/drivers/tuntap_user.c +++ b/arch/um/os-Linux/drivers/tuntap_user.c @@ -146,7 +146,7 @@ static int tuntap_open(void *data) } memset(&ifr, 0, sizeof(ifr)); ifr.ifr_flags = IFF_TAP | IFF_NO_PI; - strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name)); + strscpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name)); if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) { err = -errno; printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",