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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 2CE9AC433DB for ; Mon, 22 Feb 2021 17:23:35 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 2D49E64DE9 for ; Mon, 22 Feb 2021 17:23:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D49E64DE9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20804-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 5246 invoked by uid 550); 22 Feb 2021 17:21:48 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 16347 invoked from network); 22 Feb 2021 16:00:44 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=YGAvnzMESkS+Z4+Pab/L4bQLX/w0TQcH3GRn/tc/Ao8=; b=t6+RmEOe0FcHDkuCBmi1GLuVNYPmR6YSKQpFB7gaqGDpIt+gI81BaiC1rEbKb7eJ7x P84arTt3qW03ijOGcDQBeGh0uLgioBOz4UUkB4ENP3bSIgUmw2QTuWkKFOttZTjlycPo ySQdI4AexC7BbWqmNr3tvSRVFhU9kxndhD5nwtpyDfjkkUL+t0V8LrGXHeReTbMdGkpo cm9ODgV91GVJ4f8dVCQ9gu2yHvl2nDS9cwVALhWn4xnf0yyRFAiYPkp2tUD8DmRQZ1RB 2BteB6apH/4nk31r+ALfnyRphPPrg3z/BxEVf7AryNmPApcCaNYS3xZuJ1Yr3DQbZ8mi ALtw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=YGAvnzMESkS+Z4+Pab/L4bQLX/w0TQcH3GRn/tc/Ao8=; b=CFFWXGDd+AOLzJs0p1Z4LkeLR8H694wInjkF9aX7OlBcHXtZRzanVcqWI8D1cYEUZ2 FfUvs1P18F9BuIEC8F+NOjjZXeDkDwESWwCtCWql0IKlfxEtPyUqKVQaWX4tYHRuSXwE lvYIF/KuaYcY7M5CkXyi7gIbWxmoq+xfh3nuGj91esh8FyhkQokC7qM0LNVXDCSgbcuh 4MzMD+MA956lpIg0iHdqw55axHBEx4cJtqZaohazA0WAdIegiC/uuoxjsyI72fKJ7Fok IK+Ft18IxTIHoc4gyZoonQdskSYJmd9zVPH7nEOjjlY2+nGL1xfeMt8TvHz1Xen5pg3b 5fNQ== X-Gm-Message-State: AOAM532fiJ6GuyKQ82WyOhK9yofRL0s5moVToLgXUpUbaCsDRWjLUFP7 XEjSY4JB9DybV1tDWYl/IgE= X-Google-Smtp-Source: ABdhPJxz/wKuipbNFDoAiObiR8UrkysgBqsDub+EMSZUbWYn40+Og5eya8/Tr+lBWKfgZ2ySb0qY+w== X-Received: by 2002:aa7:dac7:: with SMTP id x7mr6672502eds.44.1614009631775; Mon, 22 Feb 2021 08:00:31 -0800 (PST) Subject: Re: [PATCH 14/20] target: Manual replacement of the deprecated strlcpy() with return values To: Romain Perier , Kees Cook , kernel-hardening@lists.openwall.com, "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210222151231.22572-1-romain.perier@gmail.com> <20210222151231.22572-15-romain.perier@gmail.com> From: Bodo Stroesser Message-ID: Date: Mon, 22 Feb 2021 17:00:30 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210222151231.22572-15-romain.perier@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit On 22.02.21 16:12, Romain Perier wrote: > The strlcpy() reads the entire source buffer first, it is dangerous if > the source buffer lenght is unbounded or possibility non NULL-terminated. > It can lead to linear read overflows, crashes, etc... > > As recommended in the deprecated interfaces [1], it should be replaced > by strscpy. > > This commit replaces all calls to strlcpy that handle the return values > by the corresponding strscpy calls with new handling of the return > values (as it is quite different between the two functions). > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy > > Signed-off-by: Romain Perier > --- > drivers/target/target_core_configfs.c | 33 +++++++++------------------------ > 1 file changed, 9 insertions(+), 24 deletions(-) > > diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c > index f04352285155..676215cd8847 100644 > --- a/drivers/target/target_core_configfs.c > +++ b/drivers/target/target_core_configfs.c > @@ -1325,16 +1325,11 @@ static ssize_t target_wwn_vendor_id_store(struct config_item *item, > /* +2 to allow for a trailing (stripped) '\n' and null-terminator */ > unsigned char buf[INQUIRY_VENDOR_LEN + 2]; > char *stripped = NULL; > - size_t len; > + ssize_t len; > ssize_t ret; > > - len = strlcpy(buf, page, sizeof(buf)); > - if (len < sizeof(buf)) { > - /* Strip any newline added from userspace. */ > - stripped = strstrip(buf); > - len = strlen(stripped); > - } > - if (len > INQUIRY_VENDOR_LEN) { > + len = strscpy(buf, page, sizeof(buf)); > + if (len == -E2BIG) { > pr_err("Emulated T10 Vendor Identification exceeds" > " INQUIRY_VENDOR_LEN: " __stringify(INQUIRY_VENDOR_LEN) > "\n"); > @@ -1381,16 +1376,11 @@ static ssize_t target_wwn_product_id_store(struct config_item *item, > /* +2 to allow for a trailing (stripped) '\n' and null-terminator */ > unsigned char buf[INQUIRY_MODEL_LEN + 2]; > char *stripped = NULL; > - size_t len; > + ssize_t len; > ssize_t ret; > > - len = strlcpy(buf, page, sizeof(buf)); > - if (len < sizeof(buf)) { > - /* Strip any newline added from userspace. */ > - stripped = strstrip(buf); > - len = strlen(stripped); > - } > - if (len > INQUIRY_MODEL_LEN) { > + len = strscpy(buf, page, sizeof(buf)); > + if (len == -E2BIG) { > pr_err("Emulated T10 Vendor exceeds INQUIRY_MODEL_LEN: " > __stringify(INQUIRY_MODEL_LEN) > "\n"); > @@ -1437,16 +1427,11 @@ static ssize_t target_wwn_revision_store(struct config_item *item, > /* +2 to allow for a trailing (stripped) '\n' and null-terminator */ > unsigned char buf[INQUIRY_REVISION_LEN + 2]; > char *stripped = NULL; > - size_t len; > + ssize_t len; > ssize_t ret; > > - len = strlcpy(buf, page, sizeof(buf)); > - if (len < sizeof(buf)) { > - /* Strip any newline added from userspace. */ > - stripped = strstrip(buf); > - len = strlen(stripped); > - } > - if (len > INQUIRY_REVISION_LEN) { > + len = strscpy(buf, page, sizeof(buf)); > + if (len == -E2BIG) { > pr_err("Emulated T10 Revision exceeds INQUIRY_REVISION_LEN: " > __stringify(INQUIRY_REVISION_LEN) > "\n"); > AFAICS, you are not only replacing strlcpy with strscpy, but also remove stripping of possible trailing '\n', and remove the necessary length check of the remaining string. -Bodo