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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9A4CC2BB9D for ; Mon, 15 Aug 2022 22:38:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350507AbiHOWgk (ORCPT ); Mon, 15 Aug 2022 18:36:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350976AbiHOW1W (ORCPT ); Mon, 15 Aug 2022 18:27:22 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F401512A54C; Mon, 15 Aug 2022 12:45:54 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AB6E8B80EA7; Mon, 15 Aug 2022 19:45:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01708C433D6; Mon, 15 Aug 2022 19:45:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660592752; bh=6ACOjqndLQ3Ih+OOe30yxTbZi6HcEEwp2lVFUhXVsv0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IeJJ0VjE2v8vHYmDKiQrD39UAj00laEBFlQ02FjbR7uiYb1ZOCb0oWPzQRqyVzMGH ubE4U/qc7C3RNBJzqtmvQbtgiyFcoqE9RPPp7kwbfLog+GkJ6dJWlwZVOorf1UnqQ1 PS73dldZaDuQ241CxNxiglJ07MdYKacfdMJRl/KE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Shengjiu Wang , Mathieu Poirier , Sasha Levin Subject: [PATCH 5.18 0840/1095] rpmsg: char: Add mutex protection for rpmsg_eptdev_open() Date: Mon, 15 Aug 2022 20:03:59 +0200 Message-Id: <20220815180504.090182580@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180429.240518113@linuxfoundation.org> References: <20220815180429.240518113@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Shengjiu Wang [ Upstream commit abe13e9a561d6b3e82b21362c0d6dd3ecd8a5b13 ] There is no mutex protection for rpmsg_eptdev_open(), especially for eptdev->ept read and write operation. It may cause issues when multiple instances call rpmsg_eptdev_open() in parallel,the return state may be success or EBUSY. Fixes: 964e8bedd5a1 ("rpmsg: char: Return an error if device already open") Signed-off-by: Shengjiu Wang Link: https://lore.kernel.org/r/1653104105-16779-1-git-send-email-shengjiu.wang@nxp.com Signed-off-by: Mathieu Poirier Signed-off-by: Sasha Levin --- drivers/rpmsg/rpmsg_char.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c index b6183d4f62a2..4f2189111494 100644 --- a/drivers/rpmsg/rpmsg_char.c +++ b/drivers/rpmsg/rpmsg_char.c @@ -120,8 +120,11 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) struct rpmsg_device *rpdev = eptdev->rpdev; struct device *dev = &eptdev->dev; - if (eptdev->ept) + mutex_lock(&eptdev->ept_lock); + if (eptdev->ept) { + mutex_unlock(&eptdev->ept_lock); return -EBUSY; + } get_device(dev); @@ -137,11 +140,13 @@ static int rpmsg_eptdev_open(struct inode *inode, struct file *filp) if (!ept) { dev_err(dev, "failed to open %s\n", eptdev->chinfo.name); put_device(dev); + mutex_unlock(&eptdev->ept_lock); return -EINVAL; } eptdev->ept = ept; filp->private_data = eptdev; + mutex_unlock(&eptdev->ept_lock); return 0; } -- 2.35.1