From patchwork Tue Nov 2 23:51:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sujit Kautkar X-Patchwork-Id: 12599873 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9D37C433F5 for ; Tue, 2 Nov 2021 23:53:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 96DD361076 for ; Tue, 2 Nov 2021 23:53:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230431AbhKBXzh (ORCPT ); Tue, 2 Nov 2021 19:55:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230059AbhKBXzg (ORCPT ); Tue, 2 Nov 2021 19:55:36 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECFB3C061714 for ; Tue, 2 Nov 2021 16:53:00 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id r5so1325094pls.1 for ; Tue, 02 Nov 2021 16:53:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=HX2l8wCAAdLIzHzPqNW+Wx3+GalJcxGcBFFOy/pfMy8=; b=WdKHPFS1fQn10Vh/sSDrziDYtODr8B3oUA9dIdpVRRs0yGjgG+qD4gCuXjzDzk3FCm 5dfhspIShYP0TxLTMJzjhtXzRzR02gqakb9gJfqSXpyfXKRdb9jPvuiq7mjOf/aojfib hqIp00Y18hse1RI8XxsS9+dcfH3gJIbRqxYd0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=HX2l8wCAAdLIzHzPqNW+Wx3+GalJcxGcBFFOy/pfMy8=; b=3sBVxDz85ffVy60I/51rI+5BdkT2ms6gE/dKJYbrjHk4icXeQqqKwJuJsY3xXT/VfE DZYFpjT0Tj53h6S0bt1oyPH7tZY9CUvGMfNRaVkfAXSRG+v5TvCvOxUZwny0JgYKwf4C w+eh7b2m0QvjgUPXelD5i4yqSGpKWIsAOxOSxVXSUrvw4q+3dpaBBDborJUfUNUMJS/v KmZGX78uyn2/MFE5IPMWo62VkBKecaR35Vfwus9yG1BJdVmqhscv+RS7bEPsZNZQ2Al2 uYavHVpUNzMlT/zBCf1Irnea2MIHrDLOAeKirEUYdwA0oBEX9HqpGQOgLebzkscNsAbq U3NA== X-Gm-Message-State: AOAM532w8hoD4cT3dqzCKvTYWiXtZX4c/JQCa1P3nNVan307P5Wn0XOi jqH+/9CL1nBUK3RBbPbNTbjQZA== X-Google-Smtp-Source: ABdhPJz+fDo0zwYcArkLroIbsxUX2fxL0DV4astnTAu1ESEmswOcAnBDXho/Sx7BRBuNOzTFOSlVdQ== X-Received: by 2002:a17:90a:6b4d:: with SMTP id x13mr10648259pjl.208.1635897180455; Tue, 02 Nov 2021 16:53:00 -0700 (PDT) Received: from sujitka-glaptop.hsd1.ca.comcast.net ([2601:646:8e00:b2f0:c31d:1b47:2691:7a67]) by smtp.gmail.com with ESMTPSA id z73sm176381pgz.23.2021.11.02.16.52.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Nov 2021 16:53:00 -0700 (PDT) From: Sujit Kautkar To: Andy Gross , Ohad Ben-Cohen Cc: Bjorn Andersson , Sibi Sankar , Matthias Kaehlcke , Stephen Boyd , Sujit Kautkar , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-remoteproc@vger.kernel.org Subject: [PATCH v3 1/2] rpmsg: glink: Fix use-after-free in qcom_glink_rpdev_release() Date: Tue, 2 Nov 2021 16:51:49 -0700 Message-Id: <20211102165137.v3.1.I2858f54e737295d746ea67e1dc0068fe63913ae5@changeid> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20211102235147.872921-1-sujitka@chromium.org> References: <20211102235147.872921-1-sujitka@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org qcom_glink_rpdev_release() sets channel->rpdev to NULL. However, with debug enabled kernel, qcom_glink_rpdev_release() gets delayed due to delayed kobject release and channel gets released by that time and triggers below kernel warning. To avoid this use-after-free, clear ept pointers during ept destroy and channel release and add a new condition in qcom_glink_rpdev_release() to access channel | BUG: KASAN: use-after-free in qcom_glink_rpdev_release+0x54/0x70 | Write of size 8 at addr ffffffaba438e8d0 by task kworker/6:1/54 | | CPU: 6 PID: 54 Comm: kworker/6:1 Not tainted 5.4.109-lockdep #16 | Hardware name: Google Lazor (rev3+) with KB Backlight (DT) | Workqueue: events kobject_delayed_cleanup | Call trace: | dump_backtrace+0x0/0x284 | show_stack+0x20/0x2c | dump_stack+0xd4/0x170 | print_address_description+0x3c/0x4a8 | __kasan_report+0x144/0x168 | kasan_report+0x10/0x18 | __asan_report_store8_noabort+0x1c/0x24 | qcom_glink_rpdev_release+0x54/0x70 | device_release+0x68/0x14c | kobject_delayed_cleanup+0x158/0x2cc | process_one_work+0x7cc/0x10a4 | worker_thread+0x80c/0xcec | kthread+0x2a8/0x314 | ret_from_fork+0x10/0x18 Signed-off-by: Sujit Kautkar --- Changes in v3: - Clear ept pointers and add extra conditions Changes in v2: - Fix typo in commit message drivers/rpmsg/qcom_glink_native.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c index e1444fefdd1c0..0c64a6f7a4f09 100644 --- a/drivers/rpmsg/qcom_glink_native.c +++ b/drivers/rpmsg/qcom_glink_native.c @@ -269,6 +269,9 @@ static void qcom_glink_channel_release(struct kref *ref) idr_destroy(&channel->riids); spin_unlock_irqrestore(&channel->intent_lock, flags); + if (channel->rpdev) + channel->rpdev->ept = NULL; + kfree(channel->name); kfree(channel); } @@ -1214,6 +1217,8 @@ static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept) channel->ept.cb = NULL; spin_unlock_irqrestore(&channel->recv_lock, flags); + channel->rpdev->ept = NULL; + /* Decouple the potential rpdev from the channel */ channel->rpdev = NULL; @@ -1371,9 +1376,12 @@ static const struct rpmsg_endpoint_ops glink_endpoint_ops = { static void qcom_glink_rpdev_release(struct device *dev) { struct rpmsg_device *rpdev = to_rpmsg_device(dev); - struct glink_channel *channel = to_glink_channel(rpdev->ept); + struct glink_channel *channel = NULL; - channel->rpdev = NULL; + if (rpdev->ept) { + channel = to_glink_channel(rpdev->ept); + channel->rpdev = NULL; + } kfree(rpdev); }