readme: taint clarifications

This commit is contained in:
Josh Poimboeuf 2014-05-01 12:15:58 -05:00
parent c85467db04
commit d76ba0b9a7
1 changed files with 11 additions and 4 deletions

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@ -205,11 +205,18 @@ ability to arbitrarily modify the kernel, with or without kpatch.
**Q. How can I detect if somebody has patched the kernel?**
We hope to create a new kernel TAINT flag which will get set whenever a patch
module is loaded. We are currently using the `TAINT_USER` flag.
When a patch module is loaded, the `TAINT_USER` flag is set. To test for it,
`cat /proc/sys/kernel/tainted` and check to see if the value of 64 has been
OR'ed in.
Also, many distros ship with cryptographically signed kernel modules, and will
taint the kernel anyway if you load an unsigned module.
Eventually we hope to have a dedicated `TAINT_KPATCH` flag instead.
Note that the `TAINT_OOT_MODULE` flag (64) will also be set, since the patch
module is built outside the Linux kernel source tree.
If your patch module is unsigned, the `TAINT_FORCED_MODULE` flag (2) will also
be set. Starting with Linux 3.15, this will be changed to the more specific
`TAINT_UNSIGNED_MODULE` (8192).
**Q. Will it destabilize my system?**