classes of bugs are found, but a failure of these extra protections do not
constitute a vulnerability alone.
-What does not constitute a security bug
----------------------------------------
+What classes of problems are not considered vulnerabilities
+-----------------------------------------------------------
In the Linux kernel's threat model, the following classes of problems are
-**NOT** considered as Linux Kernel security bugs. However, when it is believed
+**NOT** considered Linux Kernel vulnerabilities. However, when it is believed
that the kernel could do better, they should be reported, so that they can be
reviewed and fixed where reasonably possible, but they will be handled as any
regular bug:
* outdated kernels and particularly end-of-life branches are out of the scope
of the kernel's threat model: administrators are responsible for keeping
- their system up to date. For a bug to qualify as a security bug, it must be
- demonstrated that it affects actively maintained versions.
+ their system up to date. For a bug to qualify as a vulnerability, it must
+ be demonstrated that it affects actively maintained versions.
* build-level: changes to the kernel configuration that are explicitly
documented as lowering the security level (e.g. ``CONFIG_NOMMU``), or
involving tens of millions of threads, tens of thousands of CPUs,
unrealistic CPU frequencies, RAM sizes or disk capacities, network speeds).
- * issues whose reproduction requires hardware modification or emulation,
+ * bugs whose reproduction requires hardware modification or emulation,
including fake USB devices that pretend to be another one.
* as well as issues that can be triggered at a cost that is orders of
messages.
* Leaks of kernel memory addresses/pointers do not constitute an immediately
- exploitable vector and are not security bugs, though they must be reported
- and fixed.
+ exploitable vector and are not vulnerabilities, though they must be
+ reported and fixed.
* **Crafted file system images**:
* bugs triggered by mounting a corrupted or maliciously crafted file system
- image are generally not security bugs, as the kernel assumes the underlying
+ image are generally not vulnerabilities, as the kernel assumes the underlying
storage media is under the administrator's control, unless the filesystem
driver is specifically documented as being hardened against untrusted media.
- * issues that are resolved, mitigated, or detected by running a filesystem
+ * bugs that are resolved, mitigated, or detected by running a filesystem
consistency check (fsck) on the image prior to mounting.
* **Physical access**:
* **Functional and performance regressions**:
Any issue that can be mitigated by setting proper permissions and limits
- doesn't qualify as a security bug.
+ doesn't qualify as a vulnerability.