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 75407CDB47E for ; Sun, 15 Oct 2023 18:35:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229559AbjJOSfO (ORCPT ); Sun, 15 Oct 2023 14:35:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229518AbjJOSfN (ORCPT ); Sun, 15 Oct 2023 14:35:13 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 184C6AB for ; Sun, 15 Oct 2023 11:35:12 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 22056C433C7; Sun, 15 Oct 2023 18:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697394911; bh=pFSrmuuga7ikY29I8SyUWHzG5KM5UveBBnpBlfdzvzA=; h=Subject:To:Cc:From:Date:From; b=OmaHsF1jednm3m7g2aybJ84TIqtvUF1rS0C0gDS7ZeScC6gIJa8hL4JCGqbAvvjba t78ekp+LVPWxZvMXZiq7xLxvMY/CBLRp4trU3H+djEllS5R40JeL/G3fMDbwHbksFA luAxMFCiHkQhaESVQkfB6aRKTIUobdy7gxpxRQOE= Subject: FAILED: patch "[PATCH] iio: cros_ec: fix an use-after-free in" failed to apply to 5.15-stable tree To: tzungbi@kernel.org, Jonathan.Cameron@huawei.com, groeck@chromium.org, swboyd@chromium.org Cc: From: Date: Sun, 15 Oct 2023 20:35:01 +0200 Message-ID: <2023101501-conclude-partner-77d5@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 7771c8c80d62ad065637ef74ed2962983f6c5f6d # git commit -s git send-email --to '' --in-reply-to '2023101501-conclude-partner-77d5@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7771c8c80d62ad065637ef74ed2962983f6c5f6d Mon Sep 17 00:00:00 2001 From: Tzung-Bi Shih Date: Tue, 29 Aug 2023 11:06:22 +0800 Subject: [PATCH] iio: cros_ec: fix an use-after-free in cros_ec_sensors_push_data() cros_ec_sensors_push_data() reads `indio_dev->active_scan_mask` and calls iio_push_to_buffers_with_timestamp() without making sure the `indio_dev` stays in buffer mode. There is a race if `indio_dev` exits buffer mode right before cros_ec_sensors_push_data() accesses them. An use-after-free on `indio_dev->active_scan_mask` was observed. The call trace: [...] _find_next_bit cros_ec_sensors_push_data cros_ec_sensorhub_event blocking_notifier_call_chain cros_ec_irq_thread It was caused by a race condition: one thread just freed `active_scan_mask` at [1]; while another thread tried to access the memory at [2]. Fix it by calling iio_device_claim_buffer_mode() to ensure the `indio_dev` can't exit buffer mode during cros_ec_sensors_push_data(). [1]: https://elixir.bootlin.com/linux/v6.5/source/drivers/iio/industrialio-buffer.c#L1189 [2]: https://elixir.bootlin.com/linux/v6.5/source/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c#L198 Cc: stable@vger.kernel.org Fixes: aa984f1ba4a4 ("iio: cros_ec: Register to cros_ec_sensorhub when EC supports FIFO") Signed-off-by: Tzung-Bi Shih Reviewed-by: Guenter Roeck Reviewed-by: Stephen Boyd Link: https://lore.kernel.org/r/20230829030622.1571852-1-tzungbi@kernel.org Signed-off-by: Jonathan Cameron diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c index b72d39fc2434..6bfe5d6847e7 100644 --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c @@ -190,8 +190,11 @@ int cros_ec_sensors_push_data(struct iio_dev *indio_dev, /* * Ignore samples if the buffer is not set: it is needed if the ODR is * set but the buffer is not enabled yet. + * + * Note: iio_device_claim_buffer_mode() returns -EBUSY if the buffer + * is not enabled. */ - if (!iio_buffer_enabled(indio_dev)) + if (iio_device_claim_buffer_mode(indio_dev) < 0) return 0; out = (s16 *)st->samples; @@ -210,6 +213,7 @@ int cros_ec_sensors_push_data(struct iio_dev *indio_dev, iio_push_to_buffers_with_timestamp(indio_dev, st->samples, timestamp + delta); + iio_device_release_buffer_mode(indio_dev); return 0; } EXPORT_SYMBOL_GPL(cros_ec_sensors_push_data);