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=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 DEE2BC07E9A for ; Wed, 14 Jul 2021 04:05:58 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DFAAF6136E for ; Wed, 14 Jul 2021 04:05:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DFAAF6136E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4GPkSh06pQz301x for ; Wed, 14 Jul 2021 14:05:56 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.187; helo=szxga01-in.huawei.com; envelope-from=zhuangyi1@huawei.com; receiver=) X-Greylist: delayed 1199 seconds by postgrey-1.36 at boromir; Wed, 14 Jul 2021 11:22:53 AEST Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4GPfrY6ZX3z2yxV for ; Wed, 14 Jul 2021 11:22:51 +1000 (AEST) Received: from dggeml757-chm.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GPfGF6rP8zXrJg; Wed, 14 Jul 2021 08:56:37 +0800 (CST) Received: from huawei.com (10.90.53.225) by dggeml757-chm.china.huawei.com (10.1.199.137) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 14 Jul 2021 09:02:14 +0800 From: Yi Zhuang To: , Subject: [PATCH] powerpc/rtas_flash: fix a potential buffer overflow Date: Wed, 14 Jul 2021 09:16:08 +0800 Message-ID: <20210714011608.15043-1-zhuangyi1@huawei.com> X-Mailer: git-send-email 2.26.0.106.g9fadedd MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.90.53.225] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggeml757-chm.china.huawei.com (10.1.199.137) X-CFilter-Loop: Reflected X-Mailman-Approved-At: Wed, 14 Jul 2021 14:05:37 +1000 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hegdevasant@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, zhuangyi1@huawei.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Since snprintf() returns the possible output size instead of the actual output size, the available flash_msg length returned by get_validate_flash_msg may exceed the given buffer limit when simple_read_from_buffer calls copy_to_user Signed-off-by: Yi Zhuang --- arch/powerpc/kernel/rtas_flash.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c index a99179d83538..4aa6bad28556 100644 --- a/arch/powerpc/kernel/rtas_flash.c +++ b/arch/powerpc/kernel/rtas_flash.c @@ -473,6 +473,10 @@ static int get_validate_flash_msg(struct rtas_validate_flash_t *args_buf, (args_buf->update_results == VALIDATE_TMP_UPDATE)) n += snprintf(msg + n, msglen - n, "%s\n", args_buf->buf); + if (n >= msglen) { + n = msglen; + printk(KERN_ERR "FLASH: msg too long.\n"); + } } else { n = sprintf(msg, "%d\n", args_buf->status); } -- 2.26.0.106.g9fadedd