** Description changed: - Binary package hint: xorg + [Impact] + On certain higher resolution touchpads, an integer overflow can occur since their range exceeds the maximum int value. - The xf86ScaleAxis function is used to scale x and y axis values of input - devices between different resolutions. Due to internal integer overflow, - the acceptable value range for its arguments are limited below their - type (signed 32bit integer). This imposes a problem for high resolution - devices, like the wacom Intuos 4 L, which have a total horizontal - resolution of 65024. Example: when doing a scaling with a range of more - than 46340 (Sxhigh-Sxlow), the integer X will wrap into negative values, - and truncated to 0 at the end. + This issue can crop up on Lucid if the user self-compiles -wacom or uses + a backport package from a PPA. It does not affect the shipped version + of -wacom in Lucid. + + [Development Solution] + This was fixed upstream by using a 64-bit integer rather than 32-bit to extend the range. This fix is included in the upstream version of xorg-server we are shipping in natty. + + [Stable Solution] + A backport of the fix has been made for Lucid. + https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/730488/+attachment/1891113/+files/xf86-scale-high-resolution.diff + + [Test Case] + See below (requires affected hardware and rebuilding -wacom on Lucid) + + [Regression Potential] + None. No APIs are changed, and increase of the data type has no other code effects. + + [Original Report] + The xf86ScaleAxis function is used to scale x and y axis values of input devices between different resolutions. Due to internal integer overflow, the acceptable value range for its arguments are limited below their type (signed 32bit integer). This imposes a problem for high resolution devices, like the wacom Intuos 4 L, which have a total horizontal resolution of 65024. Example: when doing a scaling with a range of more than 46340 (Sxhigh-Sxlow), the integer X will wrap into negative values, and truncated to 0 at the end. Among other devices, this problem affects wacom Intuos 4 L and XL tablets when compiling the xf86-input-wacom driver version 0.10.9 and above. Previous versions work, because they don't use the xf86ScaleAxis function. With current xorg releases this problem does not happen either, because a upstream patch (http://lists.x.org/archives/xorg- devel/2010-April/007333.html) already extends the acceptable value range. A solution would be to include this patch into 10.04, because there is still quite a time till the next LTS. If there is a chance for getting this patch included into 10.04 I'm willing to make a patch specific for the current xorg-server-1.7.6 package and test it.
** Also affects: xorg-server (Ubuntu Lucid) Importance: Undecided Status: New ** Also affects: xorg-server (Ubuntu Natty) Importance: Undecided Status: Confirmed ** Changed in: xorg-server (Ubuntu Natty) Status: Confirmed => Fix Released ** Changed in: xorg-server (Ubuntu Lucid) Status: New => Fix Committed ** Changed in: xorg-server (Ubuntu Lucid) Importance: Undecided => Medium ** Changed in: xorg-server (Ubuntu Natty) Importance: Undecided => High -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in ubuntu. https://bugs.launchpad.net/bugs/730488 Title: [Lucid] xf86ScaleAxis problems with high resolution devices _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp