Some Android Wallpapers Could Crash Phone

Background "wallpaper" can cause Android phones to crash thanks to a bug with the system. At the moment it appears to be an unfortunate glitch but it could be open to abuse.

The image in question is viewable at twitter.com, and features a scene with a forest in the foreground, a lake in the midground, and mountains in the background beneath a cloudy sky at sunset.

The problem is that once set as the default wallpaper, the image causes the phone to crash. The phone then goes into a loop of restarting and crashing, with the only solution being a factory reset. That's not only time consuming but can mean a loss of data depending on the user's backup settings.

Big Number, Big Problem

The glitch affects an Android process called com.android.systemui which, in Google's own words, takes care of "Everything you see in Android that's not an app." (Source: theregister.com)

The cause appears to be a simple problem with an inconsistency with the color spaces - effectively the palettes - used by the image and by Android. The process of converting between the two involves producing a number which Android expects to be between 0 and 255. However this image produces a number above 255 which effectively causes Android to throw its hands in the air and give up.

Android 11 Will Fix Problem

Exactly which phones are affected is not 100% clear thanks to the way different devices use the Android code. It appears it mainly affects phones running Android 10, which is the most recent complete release. Android 11, which is currently in the test phase, appears to remove the glitch.

The big risk now is not just from this image, but from pranksters who study it and try to reproduce it in other images. So far there's no evidence the issue creates any security risk and instead it's purely an annoyance. (Source: androidauthority.com)

The bug has been reported to the Android Open Source Project so a fix could follow. In the meantime, it's probably safest to avoid downloading or installing any Android wallpaper.

What's Your Opinion?

Have you ever changed the wallpaper on your phone? Did you download a new image to use? If so, did you consider there'd be any risk of such a bug?