# Re: \[PATCH v2\] LSM: general protection fault in legacy\_parse\_param

- From: Christian Brauner \<brauner@kernel.org\>
- Date: 2022-01-28 08:59:23 
- List: linux-security-module
- Page: https://ratatoskr.run/linux-security-module/2022/01/221940
- Thread: https://ratatoskr.run/linux-security-module/2021/10/215728/t.md

```text
On Thu, Jan 27, 2022 at 08:51:44AM -0800, Casey Schaufler wrote:
> The usual LSM hook "bail on fail" scheme doesn't work for cases where
> a security module may return an error code indicating that it does not
> recognize an input.  In this particular case Smack sees a mount option
> that it recognizes, and returns 0. A call to a BPF hook follows, which
> returns -ENOPARAM, which confuses the caller because Smack has processed
> its data.
> 
> The SELinux hook incorrectly returns 1 on success. There was a time
> when this was correct, however the current expectation is that it
> return 0 on success. This is repaired.
> 
> Reported-by: <redacted>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---

Looks good,
Acked-by: Christian Brauner <brauner@kernel.org>
```