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 2987B246BCD; Sat, 12 Sep 2026 10:01:09 +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=1789207271; cv=none; b=bh7GDiZwzZ18U9TRdmj8V3pQHM46H0le60i3ktLvmR/iBz54qMVEJU8QhbLqBJQFQx9eNW5hjl1bAqg0goXHJBy8u+0vehj4fNOFVjbRhI7MsvFxG8kr2Z1BIg+eRpn3g2nkgjCzFav1qxJMe3WHUAcUF4btsopD2rWHTdJAi6M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789207271; c=relaxed/simple; bh=SVEZJupOepzKeDi0RT1q6tDunjoJSbZGrGO+3DNhBe0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=myWTp39EyF60iHL4XyeKeuygFUZMIQCci2ZHoDhioFAMkaPxTEBgwlEAWTBzP4vN2gM4/LHl0Gg3LXbUB9Hp1FnaYS9ueQYr2Bhoi/UsSMfGwm/eGIcVPS1ggU2UEDz1E/kdn94MXqYqM03TP0Imz87L9F1hNyUkpFsCI7kbIuk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AqHiqN71; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AqHiqN71" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E3761F000FF; Sat, 12 Sep 2026 10:01:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789207269; bh=vt0JZZkD02gr/BVsmyspsBWmXVbwbtPV53iqbiuVdDQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AqHiqN71h+H9+i0Al6sb/dOgXR3bBAcM8+2UOex5MgPGu9DE8DJQr64SfUQIqr+hP Sl7zBfyve12oac/coHqlEpmhLviExUe8IJlIS5Qqe5pHpl0op+35EI0b7NLBSJ7wqt it/mm9KZuBKdEWHT2Rvs1B/riQazwzzIIV+OHF7Q= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Sudeep Holla , Sasha Levin Subject: [PATCH 6.18 0379/1518] firmware: arm_scmi: Quiesce notifications before teardown Date: Sat, 12 Sep 2026 08:42:28 +0200 Message-ID: <20260912065632.036706837@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sudeep Holla [ Upstream commit 8e49055d0d495c9c07575ad8e111d9eaf0efb13f ] 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 Link: https://patch.msgid.link/20260714-scmi_core_fixes-v6-3-3afe499d46e3@kernel.org Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- 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 69f88b41e2b2d..529a4e5852e6e 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -3233,7 +3233,7 @@ 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); @@ -3275,17 +3275,18 @@ 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); @@ -3312,6 +3313,9 @@ 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); @@ -3324,9 +3328,6 @@ 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 9bf7f43ab868c..672c91197a68a 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 76758a736cf47..f18f98c5ab3ba 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, -- 2.53.0