In almost all circumstances, a paper cut fix will not be backported. Only paper cuts with a high importance will be submitted, and even then it's not guaranteed to be approved.
All Stable Release Updates are approved with caution. Full details about what they are and how they work can be found here, but the passage of importance is this:
Stable release updates are automatically recommended to a very large
number of users, and so it is critically important to treat them with
great caution. Therefore, when updates are proposed, they must be
accompanied by a strong rationale and present a low risk of
"It's just a one-line change!" Even the simplest of changes can cause
unexpected regressions due to lurking problems:
- In bug 81125, the upgrade regression had nothing to do with the
content of the change that triggered it: any user who had installed
the libpthread20 package would encounter a problem the next time libc6
- In bug 309674, the failure was a misbuild due to
timestamp skew in the build process. The underlying problem existed in
the source package in the original release, but would only manifest in
a small percentage of builds.
- In bug 559822, a C++ library
(wxwidgets2.8) was uploaded with no code changes. Due to an underlying
toolchain change/bug, this caused an ABI change, causing a lot of
unrelated packages to break (see bug 610975).
We never assume that any change, no matter how obvious, is completely free of regression risk.
The definition of a paper cut requires the problem to be minor, meaning the need to backport it will be low to non-existent. Only paper cuts with a high importance will be considered for SRU, and these will be few and far between.