From 1e7cbfaa66d39e78bd24df0c78b55df68176b59e Mon Sep 17 00:00:00 2001 From: Rishabh Bhatnagar Date: Wed, 4 Aug 2021 14:19:59 -0700 Subject: firmware: arm_scmi: Free mailbox channels if probe fails Mailbox channels for the base protocol are setup during probe. There can be a scenario where probe fails to acquire the base protocol due to a timeout leading to cleaning up of all device managed memory including the scmi_mailbox structure setup during mailbox_chan_setup function. | arm-scmi soc:qcom,scmi: timed out in resp(caller: version_get+0x84/0x140) | arm-scmi soc:qcom,scmi: unable to communicate with SCMI | arm-scmi: probe of soc:qcom,scmi failed with error -110 Now when a message arrives at cpu slightly after the timeout, the mailbox controller will try to call the rx_callback of the client and might end up accessing freed memory. | rx_callback+0x24/0x160 | mbox_chan_received_data+0x44/0x94 | __handle_irq_event_percpu+0xd4/0x240 This patch frees the mailbox channels setup during probe and adds some more error handling in case the probe fails. Link: https://lore.kernel.org/r/1628111999-21595-1-git-send-email-rishabhb@codeaurora.org Tested-by: Cristian Marussi Reviewed-by: Cristian Marussi Signed-off-by: Rishabh Bhatnagar Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) (limited to 'drivers') diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 00fcacd06562..b28111ea7c8b 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -1787,6 +1787,21 @@ void scmi_protocol_device_unrequest(const struct scmi_device_id *id_table) mutex_unlock(&scmi_requested_devices_mtx); } +static int scmi_cleanup_txrx_channels(struct scmi_info *info) +{ + int ret; + struct idr *idr = &info->tx_idr; + + ret = idr_for_each(idr, info->desc->ops->chan_free, idr); + idr_destroy(&info->tx_idr); + + idr = &info->rx_idr; + ret = idr_for_each(idr, info->desc->ops->chan_free, idr); + idr_destroy(&info->rx_idr); + + return ret; +} + static int scmi_probe(struct platform_device *pdev) { int ret; @@ -1833,7 +1848,7 @@ static int scmi_probe(struct platform_device *pdev) ret = scmi_xfer_info_init(info); if (ret) - return ret; + goto clear_txrx_setup; if (scmi_notification_init(handle)) dev_err(dev, "SCMI Notifications NOT available.\n"); @@ -1846,7 +1861,7 @@ static int scmi_probe(struct platform_device *pdev) ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE); if (ret) { dev_err(dev, "unable to communicate with SCMI\n"); - return ret; + goto notification_exit; } mutex_lock(&scmi_list_mutex); @@ -1885,6 +1900,12 @@ static int scmi_probe(struct platform_device *pdev) } return 0; + +notification_exit: + scmi_notification_exit(&info->handle); +clear_txrx_setup: + scmi_cleanup_txrx_channels(info); + return ret; } void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id) @@ -1896,7 +1917,6 @@ static int scmi_remove(struct platform_device *pdev) { int ret = 0, id; struct scmi_info *info = platform_get_drvdata(pdev); - struct idr *idr = &info->tx_idr; struct device_node *child; mutex_lock(&scmi_list_mutex); @@ -1920,14 +1940,7 @@ static int scmi_remove(struct platform_device *pdev) idr_destroy(&info->active_protocols); /* Safe to free channels since no more users */ - ret = idr_for_each(idr, info->desc->ops->chan_free, idr); - idr_destroy(&info->tx_idr); - - idr = &info->rx_idr; - ret = idr_for_each(idr, info->desc->ops->chan_free, idr); - idr_destroy(&info->rx_idr); - - return ret; + return scmi_cleanup_txrx_channels(info); } static ssize_t protocol_version_show(struct device *dev, -- cgit v1.2.3