| Message ID | 20180405230936.4572-1-rodrigorivascosta@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 6 Apr 2018, Rodrigo Rivas Costa wrote: > Doing `ioctl(HIDIOCGFEATURE)` in a tight loop on a hidraw device > and then disconnecting the device, or unloading the driver, can > cause a NULL pointer dereference. > > When a hidraw device is destroyed it sets 0 to `dev->exist`. > Most functions check 'dev->exist' before doing its work, but > `hidraw_get_report()` was missing that check. > > Signed-off-by: Rodrigo Rivas Costa <rodrigorivascosta@gmail.com> Applied, thank you.
diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 5fbe0f81ab2e..01b5a9f01814 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -192,6 +192,11 @@ static ssize_t hidraw_get_report(struct file *file, char __user *buffer, size_t int ret = 0, len; unsigned char report_number; + if (!hidraw_table[minor] || !hidraw_table[minor]->exist) { + ret = -ENODEV; + goto out; + } + dev = hidraw_table[minor]->hid; if (!dev->ll_driver->raw_request) {
Doing `ioctl(HIDIOCGFEATURE)` in a tight loop on a hidraw device and then disconnecting the device, or unloading the driver, can cause a NULL pointer dereference. When a hidraw device is destroyed it sets 0 to `dev->exist`. Most functions check 'dev->exist' before doing its work, but `hidraw_get_report()` was missing that check. Signed-off-by: Rodrigo Rivas Costa <rodrigorivascosta@gmail.com> --- drivers/hid/hidraw.c | 5 +++++ 1 file changed, 5 insertions(+)