From: "Mickaël Salaün" <mic@digikod.net>
To: linux-kernel@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Casey Schaufler <casey@schaufler-ca.com>,
Daniel Borkmann <daniel@iogearbox.net>,
David Drysdale <drysdale@google.com>,
"David S . Miller" <davem@davemloft.net>,
"Eric W . Biederman" <ebiederm@xmission.com>,
James Morris <james.l.morris@oracle.com>,
Jann Horn <jann@thejh.net>, Jonathan Corbet <corbet@lwn.net>,
Matthew Garrett <mjg59@srcf.ucam.org>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Kees Cook <keescook@chromium.org>,
Paul Moore <paul@paul-moore.com>,
Sargun Dhillon <sargun@sargun.me>,
"Serge E . Hallyn" <serge@hallyn.com>,
Shuah Khan <shuah@kernel.org>, Tejun Heo <tj@kernel.org>,
Thomas Graf <tgraf@suug.ch>, Will Drewry <wad@chromium.org>,
kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org,
linux-security-module@vger.kernel.org, netdev@vger.kernel.org
Subject: [kernel-hardening] Re: [PATCH net-next v7 05/10] landlock: Add LSM hooks related to filesystem
Date: Tue, 22 Aug 2017 23:59:33 +0200 [thread overview]
Message-ID: <753a3a91-23a4-bc63-27cb-12e764d3d5fc@digikod.net> (raw)
In-Reply-To: <20170821000933.13024-6-mic@digikod.net>
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On 21/08/2017 02:09, Mickaël Salaün wrote:
> Handle 33 filesystem-related LSM hooks for the Landlock filesystem
> event: LANDLOCK_SUBTYPE_EVENT_FS.
>
> A Landlock event wrap LSM hooks for similar kernel object types (e.g.
> struct file, struct path...). Multiple LSM hooks can trigger the same
> Landlock event.
>
> Landlock handle nine coarse-grained actions: read, write, execute, new,
> get, remove, ioctl, lock and fcntl. Each of them abstract LSM hook
> access control in a way that can be extended in the future.
>
> The Landlock LSM hook registration is done after other LSM to only run
> actions from user-space, via eBPF programs, if the access was granted by
> major (privileged) LSMs.
>
> Signed-off-by: Mickaël Salaün <mic@digikod.net>
> Cc: Alexei Starovoitov <ast@kernel.org>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: James Morris <james.l.morris@oracle.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Serge E. Hallyn <serge@hallyn.com>
> ---
>
> Changes since v6:
> * add 3 more sub-events: IOCTL, LOCK, FCNTL
> https://lkml.kernel.org/r/2fbc99a6-f190-f335-bd14-04bdeed35571@digikod.net
> * use the new security_add_hooks()
> * explain the -Werror=unused-function
> * constify pointers
> * cleanup headers
>
> Changes since v5:
> * split hooks.[ch] into hooks.[ch] and hooks_fs.[ch]
> * add more documentation
> * cosmetic fixes
> * rebase (SCALAR_VALUE)
>
> Changes since v4:
> * add LSM hook abstraction called Landlock event
> * use the compiler type checking to verify hooks use by an event
> * handle all filesystem related LSM hooks (e.g. file_permission,
> mmap_file, sb_mount...)
> * register BPF programs for Landlock just after LSM hooks registration
> * move hooks registration after other LSMs
> * add failsafes to check if a hook is not used by the kernel
> * allow partial raw value access form the context (needed for programs
> generated by LLVM)
>
> Changes since v3:
> * split commit
> * add hooks dealing with struct inode and struct path pointers:
> inode_permission and inode_getattr
> * add abstraction over eBPF helper arguments thanks to wrapping structs
> ---
> include/linux/lsm_hooks.h | 5 +
> security/landlock/Makefile | 7 +-
> security/landlock/common.h | 2 +
> security/landlock/hooks.c | 83 ++++++
> security/landlock/hooks.h | 177 +++++++++++++
> security/landlock/hooks_fs.c | 586 +++++++++++++++++++++++++++++++++++++++++++
> security/landlock/hooks_fs.h | 19 ++
> security/landlock/init.c | 10 +
> security/security.c | 12 +-
> 9 files changed, 899 insertions(+), 2 deletions(-)
> create mode 100644 security/landlock/hooks.c
> create mode 100644 security/landlock/hooks.h
> create mode 100644 security/landlock/hooks_fs.c
> create mode 100644 security/landlock/hooks_fs.h
> diff --git a/security/landlock/init.c b/security/landlock/init.c
> index 09acbc74abd6..1e6660fed697 100644
> --- a/security/landlock/init.c
> +++ b/security/landlock/init.c
> @@ -10,8 +10,10 @@
>
> #include <linux/bpf.h> /* enum bpf_access_type */
> #include <linux/capability.h> /* capable */
> +#include <linux/lsm_hooks.h>
>
> #include "common.h" /* LANDLOCK_* */
> +#include "hooks_fs.h"
>
>
> static inline bool bpf_landlock_is_valid_access(int off, int size,
> @@ -23,6 +25,8 @@ static inline bool bpf_landlock_is_valid_access(int off, int size,
>
> switch (prog_subtype->landlock_rule.event) {
> case LANDLOCK_SUBTYPE_EVENT_FS:
> + return landlock_is_valid_access_event_FS(off, size, type,
> + &info->reg_type, prog_subtype);
I forgot to handle LANDLOCK_SUBTYPE_EVENT_FS_{IOCTL,LOCK_FCNTL} here and
I included some hunks in the wrong patches. I will fix this in the next
series and add tests for those anyway. :)
Regards,
Mickaël
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next prev parent reply other threads:[~2017-08-22 21:59 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-21 0:09 [kernel-hardening] [PATCH net-next v7 00/10] Landlock LSM: Toward unprivileged sandboxing Mickaël Salaün
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 01/10] selftest: Enhance kselftest_harness.h with a step mechanism Mickaël Salaün
2017-08-24 2:31 ` [kernel-hardening] " Alexei Starovoitov
2017-08-25 7:58 ` Mickaël Salaün
2017-08-26 1:07 ` Alexei Starovoitov
2017-08-28 18:01 ` Shuah Khan
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 02/10] bpf: Add eBPF program subtype and is_valid_subtype() verifier Mickaël Salaün
2017-08-23 2:44 ` [kernel-hardening] " Alexei Starovoitov
2017-08-23 7:45 ` Mickaël Salaün
2017-08-24 1:22 ` Alexei Starovoitov
2017-08-28 3:48 ` James Morris
2017-08-28 3:46 ` James Morris
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 03/10] bpf,landlock: Define an eBPF program type for a Landlock rule Mickaël Salaün
2017-08-24 2:28 ` [kernel-hardening] " Alexei Starovoitov
2017-08-25 8:02 ` Mickaël Salaün
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 04/10] bpf: Define handle_fs and add a new helper bpf_handle_fs_get_mode() Mickaël Salaün
2017-08-28 4:09 ` [kernel-hardening] " James Morris
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 05/10] landlock: Add LSM hooks related to filesystem Mickaël Salaün
2017-08-22 21:59 ` Mickaël Salaün [this message]
2017-08-24 2:50 ` [kernel-hardening] " Alexei Starovoitov
2017-08-25 8:16 ` Mickaël Salaün
2017-08-26 1:16 ` Alexei Starovoitov
2017-08-27 13:31 ` Mickaël Salaün
2017-08-28 5:26 ` Alexei Starovoitov
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 06/10] seccomp,landlock: Handle Landlock events per process hierarchy Mickaël Salaün
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 07/10] landlock: Add ptrace restrictions Mickaël Salaün
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 08/10] bpf: Add a Landlock sandbox example Mickaël Salaün
2017-08-24 2:59 ` [kernel-hardening] " Alexei Starovoitov
2017-08-25 8:17 ` Mickaël Salaün
2017-09-01 10:25 ` Alban Crequy
2017-09-02 13:19 ` Mickaël Salaün
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 09/10] bpf,landlock: Add tests for Landlock Mickaël Salaün
2017-08-21 0:09 ` [kernel-hardening] [PATCH net-next v7 10/10] landlock: Add user and kernel documentation " Mickaël Salaün
2017-08-28 3:38 ` [kernel-hardening] [PATCH net-next v7 00/10] Landlock LSM: Toward unprivileged sandboxing James Morris
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