snap-confine: In snapd versions prior to 2.62, snapd failed to properly check the filetype when extracting a snap

In snapd versions prior to 2.62, snapd failed to properly check the filetype when extracting a snap. The snap format is a squashfs file-systemimage and so can contain files that are non-regular files (such as pipesor sockets etc). Various file entries within the snap squashfs image(such as icons etc) are directly read by snapd when it is extracted. Anattacker who could convince a user to install a malicious snap whichcontained non-regular files at these paths could then cause snapd to blockindefinitely trying to read from such files and cause a denial of service.

Where it's fixed