Problem Description:
Insufficient validation of user-provided font parameters
can result in an integer overflow, leading to the use of
arbitrary kernel memory as glyph data. Characters that
reference this data can be displayed on the screen, effectively
disclosing kernel memory.
Impact:
Unprivileged users may be able to access privileged
kernel data.
Such memory might contain sensitive information, such
as portions of the file cache or terminal buffers. This
information might be directly useful, or it might be leveraged
to obtain elevated privileges in some way; for example, a
terminal buffer might include a user-entered password.