diff options
Diffstat (limited to 'drivers/input/evdev.c')
| -rw-r--r-- | drivers/input/evdev.c | 63 |
1 files changed, 43 insertions, 20 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index 2d65411f6763..3524bef62be6 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -647,6 +647,47 @@ static int str_to_user(const char *str, unsigned int maxlen, void __user *p) return copy_to_user(p, str, len) ? -EFAULT : len; } +#define OLD_KEY_MAX 0x1ff +static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user *p, int compat_mode) +{ + static unsigned long keymax_warn_time; + unsigned long *bits; + int len; + + switch (_IOC_NR(cmd) & EV_MAX) { + + case 0: bits = dev->evbit; len = EV_MAX; break; + case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; + case EV_REL: bits = dev->relbit; len = REL_MAX; break; + case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; + case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; + case EV_LED: bits = dev->ledbit; len = LED_MAX; break; + case EV_SND: bits = dev->sndbit; len = SND_MAX; break; + case EV_FF: bits = dev->ffbit; len = FF_MAX; break; + case EV_SW: bits = dev->swbit; len = SW_MAX; break; + default: return -EINVAL; + } + + /* + * Work around bugs in userspace programs that like to do + * EVIOCGBIT(EV_KEY, KEY_MAX) and not realize that 'len' + * should be in bytes, not in bits. + */ + if ((_IOC_NR(cmd) & EV_MAX) == EV_KEY && _IOC_SIZE(cmd) == OLD_KEY_MAX) { + len = OLD_KEY_MAX; + if (printk_timed_ratelimit(&keymax_warn_time, 10 * 1000)) + printk(KERN_WARNING + "evdev.c(EVIOCGBIT): Suspicious buffer size %u, " + "limiting output to %zu bytes. See " + "http://userweb.kernel.org/~dtor/eviocgbit-bug.html\n", + OLD_KEY_MAX, + BITS_TO_LONGS(OLD_KEY_MAX) * sizeof(long)); + } + + return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode); +} +#undef OLD_KEY_MAX + static long evdev_do_ioctl(struct file *file, unsigned int cmd, void __user *p, int compat_mode) { @@ -733,26 +774,8 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd, if (_IOC_DIR(cmd) == _IOC_READ) { - if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) { - - unsigned long *bits; - int len; - - switch (_IOC_NR(cmd) & EV_MAX) { - - case 0: bits = dev->evbit; len = EV_MAX; break; - case EV_KEY: bits = dev->keybit; len = KEY_MAX; break; - case EV_REL: bits = dev->relbit; len = REL_MAX; break; - case EV_ABS: bits = dev->absbit; len = ABS_MAX; break; - case EV_MSC: bits = dev->mscbit; len = MSC_MAX; break; - case EV_LED: bits = dev->ledbit; len = LED_MAX; break; - case EV_SND: bits = dev->sndbit; len = SND_MAX; break; - case EV_FF: bits = dev->ffbit; len = FF_MAX; break; - case EV_SW: bits = dev->swbit; len = SW_MAX; break; - default: return -EINVAL; - } - return bits_to_user(bits, len, _IOC_SIZE(cmd), p, compat_mode); - } + if ((_IOC_NR(cmd) & ~EV_MAX) == _IOC_NR(EVIOCGBIT(0, 0))) + return handle_eviocgbit(dev, cmd, p, compat_mode); if (_IOC_NR(cmd) == _IOC_NR(EVIOCGKEY(0))) return bits_to_user(dev->key, KEY_MAX, _IOC_SIZE(cmd), |