Re: [RFC PATCH 5/6] smack: explicitly skip mediation of O_PATH file descriptors

[Casey Schaufler]

On 3/12/2025 2:21 PM, Ryan Lee wrote:
> Now that O_PATH fds are being passed to the file_open hook,
> unconditionally skip mediation of them to preserve existing behavior.
>
> Signed-off-by: Ryan Lee <ryan.lee@xxxxxxxxxxxxx>
> ---
>  security/smack/smack_lsm.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 2f65eb392bc0..c05e223bfb33 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -2062,6 +2062,10 @@ static int smack_file_open(struct file *file)
>  	struct smk_audit_info ad;
>  	int rc;
>  
> +	/* Preserve the behavior of O_PATH fd creation not being mediated */

In Smack the single line comment is discouraged. Please use

+	/*
+	 * Preserve the behavior of O_PATH fd creation not being mediated
+	 */

> +	if (file->f_flags & O_PATH)
> +		return 0;
> +
>  	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
>  	smk_ad_setfield_u_fs_path(&ad, file->f_path);
>  	rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);