Re: [PATCH 4/7] SELinux: hooks for secctx_to_lsmprop and update_lsmprop

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The hook selinux_update_lsmprop unconditionally returns 0, short-circuiting call_int_hook and preventing other LSMs from updating their properties.
--

--- Patch [4]: [PATCH 4/7] SELinux: hooks for secctx_to_lsmprop and update_lsmprop ---
commit a4558827a3696626337a00d0c47bdfbeb141eefe
Author: Casey Schaufler <[email protected]>

SELinux: hooks for secctx_to_lsmprop and update_lsmprop

This commit implements the secctx_to_lsmprop and update_lsmprop hooks for
the SELinux module. These additions allow SELinux to interact with the new
lsm_prop structures for context and property updates.

> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 0f704380a8c81..66f32dfadf9b3 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6926,6 +6926,15 @@ static int selinux_ismaclabel(const char *name)
>  	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
>  }
>  
> +static int selinux_update_lsmprop(struct lsm_prop *dest, struct lsm_prop *src,
> +				  int lsmid)
> +{
> +	if (lsmid == LSM_ID_SELINUX || lsmid == LSM_ID_UNDEF)
> +		dest->selinux.secid = src->selinux.secid;
> +
> +	return 0;

[Severity: High]
Does returning 0 unconditionally here break LSM stacking?

If security_update_lsmprop() is called with an lsmid targeted at another
module (e.g., LSM_ID_SMACK), the SELinux hook will execute first. Because 0
differs from the hook's default return value (-EOPNOTSUPP), call_int_hook()
will break the loop and return 0 immediately.

The target LSM's hook will never be reached, and it will silently fail to
update its properties.

> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=4