On 6/8/2021 4:19 PM, Kees Cook wrote:
On Sat, Jun 05, 2021 at 05:03:57PM +0200, John Wood wrote:
[...]
the kselftest to avoid the detection ;) ). So, in this version, to track
all the statistical data (info related with application crashes), the
extended attributes feature for the executable files are used. The xattr is
also used to mark the executables as "not allowed" when an attack is
detected. Then, the execve system call rely on this flag to avoid following
executions of this file.
I have some concerns about this being actually usable and not creating
DoS situations. For example, let's say an attacker had found a hard-to-hit
bug in "sudo", and starts brute forcing it. When the brute LSM notices,
it'll make "sudo" unusable for the entire system, yes?
And a reboot won't fix it, either, IIUC.
The whole point of the mitigation is to trade potential attacks against DOS.
If you're worried about DOS the whole thing is not for you.
-Andi
