Gitweb: http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f2afa7...
Commit: f2afa7711f8585ffc088ba538b9a510e0d5dca12
Parent: 5402a7349d26875f69c184badf87b88541b1cf6c
Author: Dmitry Torokhov <dmitry.torokhov@gmail.com>
AuthorDate: Fri Aug 8 11:46:53 2008 -0400
Committer: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CommitDate: Fri Aug 8 14:54:59 2008 -0400
Input: paper over a bug in Synaptics X driver
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---
drivers/input/evdev.c | 21 ++++++++++++++++++++-
1 files changed, 20 insertions(+), 1 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index ef8c2ed..a92d815 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -647,8 +647,10 @@ 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;
@@ -665,9 +667,26 @@ static int handle_eviocgbit(struct input_dev *dev, unsigned int cmd, void __user
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 %d, "
+ "limiting output to %d 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)
--
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