diff options
| author | Peter Korsgaard <jacmet@sunsite.dk> | 2011-02-25 09:30:46 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-02-27 01:52:53 -0800 |
| commit | 439581ec07fa9cf3f519dd461a2cf41cfd3adcb4 (patch) | |
| tree | 204e640e88005bfcda1176d28ecc9325fbf57ad3 | |
| parent | 5063511539bbb436ae8e4f75409561ef547f8516 (diff) | |
Input: evdev - fix evdev_write return value on partial writes
As was recently brought up on the busybox list
(http://lists.busybox.net/pipermail/busybox/2011-January/074565.html),
evdev_write doesn't properly check the count argument, which will
lead to a return value > count on partial writes if the remaining bytes
are accessible - causing userspace confusion.
Fix it by only handling each full input_event structure and return -EINVAL
if less than 1 struct was written, similar to how it is done in evdev_read.
Reported-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
| -rw-r--r-- | drivers/input/evdev.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index c8471a2552e..7f42d3a454d 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -321,6 +321,9 @@ static ssize_t evdev_write(struct file *file, const char __user *buffer, struct input_event event; int retval; + if (count < input_event_size()) + return -EINVAL; + retval = mutex_lock_interruptible(&evdev->mutex); if (retval) return retval; @@ -330,17 +333,16 @@ static ssize_t evdev_write(struct file *file, const char __user *buffer, goto out; } - while (retval < count) { - + do { if (input_event_from_user(buffer + retval, &event)) { retval = -EFAULT; goto out; } + retval += input_event_size(); input_inject_event(&evdev->handle, event.type, event.code, event.value); - retval += input_event_size(); - } + } while (retval + input_event_size() <= count); out: mutex_unlock(&evdev->mutex); |