6.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Aleksa Savic savicaleksa83@gmail.com
[ Upstream commit d02abd57e79469a026213f7f5827a98d909f236a ]
Through hidraw, userspace can cause a status report to be sent from the device. The parsing in ccp_raw_event() may happen in parallel to a send_usb_cmd() call (which resets the completion for tracking the report) if it's running on a different CPU where bottom half interrupts are not disabled.
Add a spinlock around the complete_all() in ccp_raw_event() and reinit_completion() in send_usb_cmd() to prevent race issues.
Fixes: 40c3a4454225 ("hwmon: add Corsair Commander Pro driver") Signed-off-by: Aleksa Savic savicaleksa83@gmail.com Acked-by: Marius Zachmann mail@mariuszachmann.de Link: https://lore.kernel.org/r/20240504092504.24158-4-savicaleksa83@gmail.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/corsair-cpro.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/drivers/hwmon/corsair-cpro.c b/drivers/hwmon/corsair-cpro.c index 6ab4d2478b1fd..3e63666a61bd6 100644 --- a/drivers/hwmon/corsair-cpro.c +++ b/drivers/hwmon/corsair-cpro.c @@ -16,6 +16,7 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/spinlock.h> #include <linux/types.h>
#define USB_VENDOR_ID_CORSAIR 0x1b1c @@ -77,6 +78,8 @@ struct ccp_device { struct hid_device *hdev; struct device *hwmon_dev; + /* For reinitializing the completion below */ + spinlock_t wait_input_report_lock; struct completion wait_input_report; struct mutex mutex; /* whenever buffer is used, lock before send_usb_cmd */ u8 *cmd_buffer; @@ -118,7 +121,15 @@ static int send_usb_cmd(struct ccp_device *ccp, u8 command, u8 byte1, u8 byte2, ccp->cmd_buffer[2] = byte2; ccp->cmd_buffer[3] = byte3;
+ /* + * Disable raw event parsing for a moment to safely reinitialize the + * completion. Reinit is done because hidraw could have triggered + * the raw event parsing and marked the ccp->wait_input_report + * completion as done. + */ + spin_lock_bh(&ccp->wait_input_report_lock); reinit_completion(&ccp->wait_input_report); + spin_unlock_bh(&ccp->wait_input_report_lock);
ret = hid_hw_output_report(ccp->hdev, ccp->cmd_buffer, OUT_BUFFER_SIZE); if (ret < 0) @@ -136,11 +147,12 @@ static int ccp_raw_event(struct hid_device *hdev, struct hid_report *report, u8 struct ccp_device *ccp = hid_get_drvdata(hdev);
/* only copy buffer when requested */ - if (completion_done(&ccp->wait_input_report)) - return 0; - - memcpy(ccp->buffer, data, min(IN_BUFFER_SIZE, size)); - complete_all(&ccp->wait_input_report); + spin_lock(&ccp->wait_input_report_lock); + if (!completion_done(&ccp->wait_input_report)) { + memcpy(ccp->buffer, data, min(IN_BUFFER_SIZE, size)); + complete_all(&ccp->wait_input_report); + } + spin_unlock(&ccp->wait_input_report_lock);
return 0; } @@ -515,7 +527,9 @@ static int ccp_probe(struct hid_device *hdev, const struct hid_device_id *id)
ccp->hdev = hdev; hid_set_drvdata(hdev, ccp); + mutex_init(&ccp->mutex); + spin_lock_init(&ccp->wait_input_report_lock); init_completion(&ccp->wait_input_report);
hid_device_io_start(hdev);