From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54AF344CAC9 for ; Tue, 14 Jul 2026 12:58:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784033922; cv=none; b=Ntpl0IvdDSC+8bfjyszz+GiZoYmVvG9ZIzxg6uEGA4QLGPbxwBL2+ApKCLq59NEfiMPAjqbVG8dOdjbP/jqrJWkcaHuVtskMk39WQEnpURjeb4g0pF1RTsAx2KtUdqTOKivAzWmQtnwJvYlGltCgWtW1yeIDqT0Ohl90Uj+Mubk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784033922; c=relaxed/simple; bh=Xb0MhSg8Hf6ZtX64aqLUF5KPXWgsuQtn0815kSvtq+U=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=WxIwN3646p+5bOQoBP5T8ScrZSQ4i6xZjXeFgYkeVWHDZrMn0+9+OUn1oQpIS9q9e0A/FHCcRvLUeb+Y/lEDr43KI6+/v0wYdv67VF4DDxT4wcjZ3BF/vy3BjZzIwor8iVl8dEeKn/tor28oBfS+jAU2GrYhp25UjUVLEEoZTh4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Qpv2yZMo; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Qpv2yZMo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C9B11F00A3D; Tue, 14 Jul 2026 12:58:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784033920; bh=QOQi0GQwy8LOev89x4shyoqxLybJwHsxamnktAUjmeI=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Qpv2yZMoV0IwLkDWYBeTujtcCkPjxoO392MiDs1lu7Pk/naBHnxQnDT/ZrjwOh/ig EsonaUbiHchwnW1+LgZdbAhqGSmKVp5DN9oGY/4vBHSnU/7cCAISCtV+d0vbzP+zbx nS0nTcfU8MoW9AR8IPzK7Eqx6fiMHcOoaY3jg8S/2AyLFkIQ3s3SQqp/NDhRnqh1cW M11h0mAnRtXqK3tCFLUHSlqjYZZec5IN6f26nVlkL81NyMvEIriWCd9mmn4UgtNOht gs5FFfQZWNL49SmSVkOrwOhqFL0LbVC5Zw4z/kpze8Vgrqs6uRtTBTTSPk10P7ykHf 58prhXcvKiZyg== From: Sudeep Holla Date: Tue, 14 Jul 2026 13:56:22 +0100 Subject: [PATCH v6 03/16] firmware: arm_scmi: Quiesce notifications before teardown Precedence: bulk X-Mailing-List: arm-scmi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260714-scmi_core_fixes-v6-3-3afe499d46e3@kernel.org> References: <20260714-scmi_core_fixes-v6-0-3afe499d46e3@kernel.org> In-Reply-To: <20260714-scmi_core_fixes-v6-0-3afe499d46e3@kernel.org> To: arm-scmi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Cristian Marussi X-Mailer: b4 0.15.2 scmi_notification_exit() clears and releases the notification instance, but transport callbacks can still deliver incoming notifications until the TX/RX channels are freed. During remove, an RX interrupt in that window can enter scmi_notify() while notification state is being torn down and then dereference freed memory. The same ordering exists on the probe error path after notification initialization. The notification late-init worker has a separate lifetime issue: protocol event registration queues ni->init_work on the system workqueue, so destroying ni->notify_wq does not drain that work. If the devres group is released while init_work is still pending or running, the late-init worker can dereference the freed notification instance. Quiesce the notification core before TX/RX channels are torn down, then clean up the channels before releasing the notification core resources. Use disable_work_sync() so future late-init queueing is rejected and any already queued or running late-init work has completed before channel teardown starts. Fixes: 1e7cbfaa66d3 ("firmware: arm_scmi: Free mailbox channels if probe fails") Reported-by: Sashiko Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 13 +++++++------ drivers/firmware/arm_scmi/notify.c | 21 +++++++++++++++++++++ drivers/firmware/arm_scmi/notify.h | 1 + 3 files changed, 29 insertions(+), 6 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 52aff3aded4c..ec373595f955 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -3325,7 +3325,7 @@ static int scmi_probe(struct platform_device *pdev) dev_err(dev, "%s", err_str); return 0; } - goto notification_exit; + goto raw_mode_cleanup; } mutex_lock(&scmi_list_mutex); @@ -3367,17 +3367,18 @@ static int scmi_probe(struct platform_device *pdev) return 0; -notification_exit: +raw_mode_cleanup: if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) scmi_raw_mode_cleanup(info->raw); - scmi_notification_exit(&info->handle); clear_dev_req_notifier: blocking_notifier_chain_unregister(&scmi_requested_devices_nh, &info->dev_req_nb); clear_bus_notifier: bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); clear_txrx_setup: + scmi_notification_quiesce(&info->handle); scmi_cleanup_txrx_channels(info); + scmi_notification_exit(&info->handle); clear_ida: ida_free(&scmi_id, info->id); @@ -3404,6 +3405,9 @@ static void scmi_remove(struct platform_device *pdev) blocking_notifier_chain_unregister(&scmi_requested_devices_nh, &info->dev_req_nb); + /* Stop transport callbacks before tearing down notifications. */ + scmi_notification_quiesce(&info->handle); + scmi_cleanup_txrx_channels(info); scmi_notification_exit(&info->handle); mutex_lock(&info->protocols_mtx); @@ -3416,9 +3420,6 @@ static void scmi_remove(struct platform_device *pdev) bus_unregister_notifier(&scmi_bus_type, &info->bus_nb); - /* Safe to free channels since no more users */ - scmi_cleanup_txrx_channels(info); - ida_free(&scmi_id, info->id); } diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c index 40ec184eedae..3239c28d6fa9 100644 --- a/drivers/firmware/arm_scmi/notify.c +++ b/drivers/firmware/arm_scmi/notify.c @@ -1706,6 +1706,25 @@ int scmi_notification_init(struct scmi_handle *handle) return -ENOMEM; } +/** + * scmi_notification_quiesce() - Stop notification late initialization + * @handle: The handle identifying the platform instance to quiesce + * + * Prevent new late-init work from being queued and wait for any already queued + * or running late-init work to complete before transport channels are torn + * down. + */ +void scmi_notification_quiesce(struct scmi_handle *handle) +{ + struct scmi_notify_instance *ni; + + ni = scmi_notification_instance_data_get(handle); + if (!ni) + return; + + disable_work_sync(&ni->init_work); +} + /** * scmi_notification_exit() - Shutdown and clean Notification core * @handle: The handle identifying the platform instance to shutdown @@ -1717,6 +1736,8 @@ void scmi_notification_exit(struct scmi_handle *handle) ni = scmi_notification_instance_data_get(handle); if (!ni) return; + + scmi_notification_quiesce(handle); scmi_notification_instance_data_set(handle, NULL); /* Destroy while letting pending work complete */ diff --git a/drivers/firmware/arm_scmi/notify.h b/drivers/firmware/arm_scmi/notify.h index 76758a736cf4..f18f98c5ab3b 100644 --- a/drivers/firmware/arm_scmi/notify.h +++ b/drivers/firmware/arm_scmi/notify.h @@ -82,6 +82,7 @@ struct scmi_protocol_events { }; int scmi_notification_init(struct scmi_handle *handle); +void scmi_notification_quiesce(struct scmi_handle *handle); void scmi_notification_exit(struct scmi_handle *handle); int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id, const struct scmi_protocol_handle *ph, -- 2.43.0