[PATCH v9 1/5] Landlock: Add abstract unix socket connect restriction

[Mickaël Salaün]

On Wed, Aug 14, 2024 at 12:22:19AM -0600, Tahera Fahimi wrote:
> This patch introduces a new "scoped" attribute to the landlock_ruleset_attr
> that can specify "LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET" to scope
> abstract Unix sockets from connecting to a process outside of
> the same landlock domain. It implements two hooks, unix_stream_connect
> and unix_may_send to enforce this restriction.
> 
> Closes: https://github.com/landlock-lsm/linux/issues/7
> Signed-off-by: Tahera Fahimi <fahimitahera at gmail.com>
> 
> ---

> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
> index 03b470f5a85a..20d2a8b5aa42 100644
> --- a/security/landlock/syscalls.c
> +++ b/security/landlock/syscalls.c
> @@ -97,8 +97,9 @@ static void build_check_abi(void)
>  	 */
>  	ruleset_size = sizeof(ruleset_attr.handled_access_fs);
>  	ruleset_size += sizeof(ruleset_attr.handled_access_net);
> +	ruleset_size += sizeof(ruleset_attr.scoped);
>  	BUILD_BUG_ON(sizeof(ruleset_attr) != ruleset_size);
> -	BUILD_BUG_ON(sizeof(ruleset_attr) != 16);
> +	BUILD_BUG_ON(sizeof(ruleset_attr) != 24);
>  
>  	path_beneath_size = sizeof(path_beneath_attr.allowed_access);
>  	path_beneath_size += sizeof(path_beneath_attr.parent_fd);
> @@ -149,7 +150,7 @@ static const struct file_operations ruleset_fops = {
>  	.write = fop_dummy_write,
>  };
>  
> -#define LANDLOCK_ABI_VERSION 5
> +#define LANDLOCK_ABI_VERSION 6

Each test need to pass with each commit (not only this one BTW), so we
need to update the abi_version test with this commit.  To be sure that
everything is OK, you can run `check-linux.sh all` on each commit.