From patchwork Thu Dec 16 12:51:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiasheng Jiang X-Patchwork-Id: 525420 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 4E4F1C433F5 for ; Thu, 16 Dec 2021 12:51:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236963AbhLPMvo (ORCPT ); Thu, 16 Dec 2021 07:51:44 -0500 Received: from smtp25.cstnet.cn ([159.226.251.25]:40766 "EHLO cstnet.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S234278AbhLPMvo (ORCPT ); Thu, 16 Dec 2021 07:51:44 -0500 Received: from localhost.localdomain (unknown [124.16.138.126]) by APP-05 (Coremail) with SMTP id zQCowAD3_wNKNrthqy92Aw--.53328S2; Thu, 16 Dec 2021 20:51:22 +0800 (CST) From: Jiasheng Jiang To: gregkh@linuxfoundation.org, jirislaby@kernel.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Jiasheng Jiang Subject: [PATCH v2] serial: pch_uart: potential dereference of null pointer Date: Thu, 16 Dec 2021 20:51:21 +0800 Message-Id: <20211216125121.399938-1-jiasheng@iscas.ac.cn> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-CM-TRANSID: zQCowAD3_wNKNrthqy92Aw--.53328S2 X-Coremail-Antispam: 1UD129KBjvdXoWrKry5XFW8Gr4xJw4ftrWDJwb_yoWkGFb_C3 Z7Xwnxur1qva9Yy3ZrJry5Gryav3yfZFs5uFn2ga9xXFW5XF1kJ34qqr9xJw47Gr4DArZx t3srWrySkr4DujkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbcxFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Cr0_ Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xII jxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr 1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7MxkIecxEwVAFwVW5JwCF 04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r 18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIxkGc2Ij64vI r41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr 1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAI cVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VUjSfO5UUUUU== X-Originating-IP: [124.16.138.126] X-CM-SenderInfo: pmld2xxhqjqxpvfd2hldfou0/ Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org The return value of dma_alloc_coherent() needs to be checked. To avoid dereference of null pointer in case of the failure of alloc. Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/") Signed-off-by: Jiasheng Jiang --- Changelog: v1 -> v2 *Change 1. Add the dev_err when dma_alloc_coherent failed. --- drivers/tty/serial/pch_uart.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index f0351e6f0ef6..d19ed7da24fa 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -745,6 +745,14 @@ static void pch_request_dma(struct uart_port *port) /* Get Consistent memory for DMA */ priv->rx_buf_virt = dma_alloc_coherent(port->dev, port->fifosize, &priv->rx_buf_dma, GFP_KERNEL); + if (!priv->rx_buf_virt) { + dev_err(priv->port.dev, "%s:dma_alloc_coherent FAILS(Rx)\n", + __func__); + dma_release_channel(priv->chan_tx); + priv->chan_tx = NULL; + return; + } + priv->chan_rx = chan; }