diff options
| author | Heiner Kallweit <hkallweit1@gmail.com> | 2016-03-10 20:52:21 +0100 |
|---|---|---|
| committer | Jiri Kosina <jkosina@suse.cz> | 2016-03-15 15:28:55 +0100 |
| commit | 1d1b564ff852944a10b524f21dfb78818bd43f52 (patch) | |
| tree | 57e8a59d8488e81b230222c474fd337572c353c2 /drivers/hid | |
| parent | 43a4a04d4ddb268373d5857c7a7bcbe3658e5b48 (diff) | |
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 <hkallweit1@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
| -rw-r--r-- | drivers/hid/hid-thingm.c | 31 |
1 files 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[] = { |