Limit amount of data that can be written into an evdev instance at a given time to 4096 bytes (170 input events) to avoid holding evdev->mutex for too long and starving other users. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> --- drivers/input/evdev.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index a8ce3d140722..eb4906552ac8 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -498,6 +498,13 @@ static ssize_t evdev_write(struct file *file, const char __user *buffer, struct input_event event; int retval = 0; + /* + * Limit amount of data we inject into the input subsystem so that + * we do not hold evdev->mutex for too long. 4096 bytes corresponds + * to 170 input events. + */ + count = min(count, 4096); + if (count != 0 && count < input_event_size()) return -EINVAL; -- 2.46.0.184.g6999bdac58-goog -- Dmitry
