Re: [RFC PATCH v9 05/16] ipe: add userspace interface
On Tue, Jan 31, 2023 at 11:49:44AM +0100, Roberto Sassu wrote:
On Mon, 2023-01-30 at 14:57 -0800, Fan Wu wrote:
> From: Deven Bowers <deven.desai(a)linux.microsoft.com>
> +
> +/**
> + * new_policy - Write handler for the securityfs node, "ipe/new_policy".
> + * @f: Supplies a file structure representing the securityfs node.
> + * @data: Suppleis a buffer passed to the write syscall.
Typo: Suppleis.
Thanks for spotting the typos!
> + * @len: Supplies the length of @data.
> + * @offset: unused.
> + *
> + * Return:
> + * * >0 - Success, Length of buffer written
> + * * <0 - Error
> + */
> +static ssize_t new_policy(struct file *f, const char __user *data,
> + size_t len, loff_t *offset)
> +{
> + int rc = 0;
> + char *copy = NULL;
> + struct ipe_policy *p = NULL;
> +
> + if (!file_ns_capable(f, &init_user_ns, CAP_MAC_ADMIN))
> + return -EPERM;
> +
> + copy = memdup_user_nul(data, len);
> + if (IS_ERR(copy)) {
> + rc = PTR_ERR(copy);
> + goto err;
> + }
> +
> + p = ipe_new_policy(NULL, 0, copy, len);
> + if (IS_ERR(p)) {
> + rc = PTR_ERR(p);
> + goto err;
> + }
> +
> + rc = ipe_new_policyfs_node(p);
> + if (rc)
> + goto err;
Uhm, don't you need to do cleanup of allocated memory or revert the
actions of ipe_new_policy()?
Yes that should be cleaned up but should be done in ipe_new_policy instead,
will add a ipe_free_policy call at the end. Thanks for pointing that out.
I would like more to see all the functions managing the policy
together. If the patch is too long, you could further split by adding
the helpers (that don't directly deal with the policy) in a separate
patch.
Here you would simply instantiate dirs/files in securityfs and call the
existing functions previously introduced.
Roberto
I will try to split them in the next version. Thanks for the suggestion.
-Fan