From patchwork Mon Aug 14 12:55:01 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinjie Ruan X-Patchwork-Id: 13352811 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 139A6C001DB for ; Mon, 14 Aug 2023 12:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:CC :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=UxjY1OIBjISnxpT9aqIdHPEJA/NdxysdxrMzbPAMbMg=; b=dO443jvN34V1Ou sMz1D//k0lyV7atmHIkSSwRbS35cxkycb1iEGNUY7ecHqpsIVBkvh15bV9jHYvOur3GhdE+Qwd2Lu +wesujU2RP3ghKAB1XcubZbLt166pe6G3sWw7RAwgNjHwAOrIFGQgVVPQJkisUxZwRObQ0ONIycN3 Xji6UgUb1baoElWALiiwV3iFnuFD5ODEIyew6t8XPHau5aMJ8XkBk9p1oWCrtuuJrhyXnQBVwgrB6 NrQhbl5lgfKLYVh94OXni+ydmagjaYJ7IYh+5AENZZFT29Z9pZbKlE2TktSVlZ2lKQQKwMVN33cLO Y1JLmAjXeUQFflIO9wHA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qVX6m-00H5Xc-2o; Mon, 14 Aug 2023 12:55:44 +0000 Received: from szxga02-in.huawei.com ([45.249.212.188]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qVX6j-00H5WK-2J for linux-arm-kernel@lists.infradead.org; Mon, 14 Aug 2023 12:55:43 +0000 Received: from kwepemi500008.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RPZ6R658TzNnFw; Mon, 14 Aug 2023 20:51:59 +0800 (CST) Received: from huawei.com (10.90.53.73) by kwepemi500008.china.huawei.com (7.221.188.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Mon, 14 Aug 2023 20:55:30 +0800 From: Ruan Jinjie To: , , Alexander Shishkin , Maxime Coquelin , Alexandre Torgue CC: Subject: [PATCH -next] stm class: Switch to memdup_user_nul() helper Date: Mon, 14 Aug 2023 20:55:01 +0800 Message-ID: <20230814125501.303210-1-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi500008.china.huawei.com (7.221.188.139) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230814_055541_960830_6BF09C9A X-CRM114-Status: UNSURE ( 9.65 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Although stm_write() use the kbuf with its count, the last byte of kbuf is not initialized and there may be problems. Use memdup_user_nul() helper instead of open-coding to simplify the code and fix the above issue. Signed-off-by: Ruan Jinjie --- drivers/hwtracing/stm/core.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 534fbefc7f6a..342d0ab6e8ca 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -645,15 +645,9 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf, return err; } - kbuf = kmalloc(count + 1, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - err = copy_from_user(kbuf, buf, count); - if (err) { - kfree(kbuf); - return -EFAULT; - } + kbuf = memdup_user_nul(buf, count); + if (IS_ERR(kbuf)) + return PTR_ERR(kbuf); pm_runtime_get_sync(&stm->dev);