From 1d1b564ff852944a10b524f21dfb78818bd43f52 Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Thu, 10 Mar 2016 20:52:21 +0100 Subject: [PATCH] hid: thingm: reorder calls in thingm_probe When reviewing another thingm patch Benjamin Tissoires pointed out the following: "The problem here is that hid_hw_start() is called before thingm_version() which allows user space to briefly introduce races between thingm_version() and any hidraw requests. The mutex will not help here as it is initialized after hid_hw_start() and only used for protecting the concurrent access of the rgb." Avoid this possible issue by calling hid_hw_start() later in the probe function. Signed-off-by: Heiner Kallweit Signed-off-by: Jiri Kosina --- drivers/hid/hid-thingm.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/drivers/hid/hid-thingm.c b/drivers/hid/hid-thingm.c index f4196ac25a64..847a497cd472 100644 --- a/drivers/hid/hid-thingm.c +++ b/drivers/hid/hid-thingm.c @@ -216,17 +216,13 @@ static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id) err = hid_parse(hdev); if (err) - goto error; - - err = hid_hw_start(hdev, HID_CONNECT_HIDRAW); - if (err) - goto error; + return err; mutex_init(&tdev->lock); err = thingm_version(tdev); if (err) - goto stop; + return err; hid_dbg(hdev, "firmware version: %c.%c\n", tdev->version.major, tdev->version.minor); @@ -237,17 +233,18 @@ static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id) if (!tdev->fwinfo) { hid_err(hdev, "unsupported firmware %c\n", tdev->version.major); - err = -ENODEV; - goto stop; + return -ENODEV; } tdev->rgb = devm_kzalloc(&hdev->dev, sizeof(struct thingm_rgb) * tdev->fwinfo->numrgb, GFP_KERNEL); - if (!tdev->rgb) { - err = -ENOMEM; - goto stop; - } + if (!tdev->rgb) + return -ENOMEM; + + err = hid_hw_start(hdev, HID_CONNECT_HIDRAW); + if (err) + return err; for (i = 0; i < tdev->fwinfo->numrgb; ++i) { struct thingm_rgb *rgb = tdev->rgb + i; @@ -255,15 +252,13 @@ static int thingm_probe(struct hid_device *hdev, const struct hid_device_id *id) rgb->tdev = tdev; rgb->num = tdev->fwinfo->first + i; err = thingm_init_rgb(rgb); - if (err) - goto stop; + if (err) { + hid_hw_stop(hdev); + return err; + } } return 0; -stop: - hid_hw_stop(hdev); -error: - return err; } static const struct hid_device_id thingm_table[] = { -- 2.34.1