diff options
| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2024-08-15 11:41:53 -0700 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2024-08-23 23:51:14 -0700 |
| commit | 6994d8b84bfd71431bfccb5baf84a827086d48a5 (patch) | |
| tree | 9b6c1763d2a1d15abbfb60836dd3e15117ec354a | |
| parent | 6c65914a40d33e96ceedc757be0129139cdf7852 (diff) | |
Input: evdev - limit amount of data for writes
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.
Reviewed-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://lore.kernel.org/r/Zr5L8TUzkJcB9HcF@google.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
| -rw-r--r-- | drivers/input/evdev.c | 7 |
1 files changed, 7 insertions, 0 deletions
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; |