diff options
| author | Sean Young <sean@mess.org> | 2018-07-28 12:11:15 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2018-07-30 15:19:53 +0300 |
| commit | f5dbee6e3881b1dbfdcc36008d48bd29549ab2f4 (patch) | |
| tree | 0c40f47cfe5fd713d664009851b11b0439f094ad /drivers/media | |
| parent | 92cab799bbc6fa1fca84bd1692285a5f926c17e9 (diff) | |
| download | linux-f5dbee6e3881b1dbfdcc36008d48bd29549ab2f4.tar.xz | |
media: rc: read out of bounds if bpf reports high protocol number
The repeat period is read from a static array. If a keydown event is
reported from bpf with a high protocol number, we read out of bounds. This
is unlikely to end up with a reasonable repeat period at the best of times,
in which case no timely key up event is generated.
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/rc/rc-main.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c index 2e222d9ee01f..ca68e1d2b2f9 100644 --- a/drivers/media/rc/rc-main.c +++ b/drivers/media/rc/rc-main.c @@ -679,6 +679,14 @@ static void ir_timer_repeat(struct timer_list *t) spin_unlock_irqrestore(&dev->keylock, flags); } +static unsigned int repeat_period(int protocol) +{ + if (protocol >= ARRAY_SIZE(protocols)) + return 100; + + return protocols[protocol].repeat_period; +} + /** * rc_repeat() - signals that a key is still pressed * @dev: the struct rc_dev descriptor of the device @@ -691,7 +699,7 @@ void rc_repeat(struct rc_dev *dev) { unsigned long flags; unsigned int timeout = nsecs_to_jiffies(dev->timeout) + - msecs_to_jiffies(protocols[dev->last_protocol].repeat_period); + msecs_to_jiffies(repeat_period(dev->last_protocol)); struct lirc_scancode sc = { .scancode = dev->last_scancode, .rc_proto = dev->last_protocol, .keycode = dev->keypressed ? dev->last_keycode : KEY_RESERVED, @@ -803,7 +811,7 @@ void rc_keydown(struct rc_dev *dev, enum rc_proto protocol, u32 scancode, if (dev->keypressed) { dev->keyup_jiffies = jiffies + nsecs_to_jiffies(dev->timeout) + - msecs_to_jiffies(protocols[protocol].repeat_period); + msecs_to_jiffies(repeat_period(protocol)); mod_timer(&dev->timer_keyup, dev->keyup_jiffies); } spin_unlock_irqrestore(&dev->keylock, flags); |