When more than one security module is exporting data to audit and
networking sub-systems a single 32 bit integer is no longer
sufficient to represent the data. Add a structure to be used instead.
The lsmblob structure definition is intended to keep the LSM
specific information private to the individual security modules.
The module specific information is included in a new set of
header files under include/lsm. Each security module is allowed
to define the information included for its use in the lsmblob.
SELinux includes a u32 secid. Smack includes a pointer into its
global label list. The conditional compilation based on feature
inclusion is contained in the include/lsm files.
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
include/linux/lsm/apparmor.h | 17 +++++++++++++++++
include/linux/lsm/bpf.h | 16 ++++++++++++++++
include/linux/lsm/selinux.h | 16 ++++++++++++++++
include/linux/lsm/smack.h | 17 +++++++++++++++++
include/linux/security.h | 20 ++++++++++++++++++++
5 files changed, 86 insertions(+)
create mode 100644 include/linux/lsm/apparmor.h
create mode 100644 include/linux/lsm/bpf.h
create mode 100644 include/linux/lsm/selinux.h
create mode 100644 include/linux/lsm/smack.h
diff --git a/include/linux/lsm/apparmor.h b/include/linux/lsm/apparmor.h
new file mode 100644
index 000000000000..8ff1cd899a20
--- /dev/null
+++ b/include/linux/lsm/apparmor.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Linux Security Module interface to other subsystems.
+ * AppArmor presents a single u32 value which is known as a secid.
+ */
+#ifndef __LINUX_LSM_APPARMOR_H
+#define __LINUX_LSM_APPARMOR_H
+
+struct aa_label;
+
+struct lsmblob_apparmor {
+#ifdef CONFIG_SECURITY_APPARMOR
+ struct aa_label *label;
+#endif
+};
+
+#endif /* ! __LINUX_LSM_APPARMOR_H */
diff --git a/include/linux/lsm/bpf.h b/include/linux/lsm/bpf.h
new file mode 100644
index 000000000000..48abdcd82ded
--- /dev/null
+++ b/include/linux/lsm/bpf.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Linux Security Module interface to other subsystems.
+ * BPF may present a single u32 value.
+ */
+#ifndef __LINUX_LSM_BPF_H
+#define __LINUX_LSM_BPF_H
+#include <linux/types.h>
+
+struct lsmblob_bpf {
+#ifdef CONFIG_BPF_LSM
+ u32 secid;
+#endif
+};
+
+#endif /* ! __LINUX_LSM_BPF_H */
diff --git a/include/linux/lsm/selinux.h b/include/linux/lsm/selinux.h
new file mode 100644
index 000000000000..fd16456b36ac
--- /dev/null
+++ b/include/linux/lsm/selinux.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Linux Security Module interface to other subsystems.
+ * SELinux presents a single u32 value which is known as a secid.
+ */
+#ifndef __LINUX_LSM_SELINUX_H
+#define __LINUX_LSM_SELINUX_H
+#include <linux/types.h>
+
+struct lsmblob_selinux {
+#ifdef CONFIG_SECURITY_SELINUX
+ u32 secid;
+#endif
+};
+
+#endif /* ! __LINUX_LSM_SELINUX_H */
diff --git a/include/linux/lsm/smack.h b/include/linux/lsm/smack.h
new file mode 100644
index 000000000000..2018f288302f
--- /dev/null
+++ b/include/linux/lsm/smack.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Linux Security Module interface to other subsystems.
+ * Smack presents a pointer into the global Smack label list.
+ */
+#ifndef __LINUX_LSM_SMACK_H
+#define __LINUX_LSM_SMACK_H
+
+struct smack_known;
+
+struct lsmblob_smack {
+#ifdef CONFIG_SECURITY_SMACK
+ struct smack_known *skp;
+#endif
+};
+
+#endif /* ! __LINUX_LSM_SMACK_H */
diff --git a/include/linux/security.h b/include/linux/security.h
index 1390f1efb4f0..0057a22137e8 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -34,6 +34,10 @@
#include <linux/sockptr.h>
#include <linux/bpf.h>
#include <uapi/linux/lsm.h>
+#include <linux/lsm/selinux.h>
+#include <linux/lsm/smack.h>
+#include <linux/lsm/apparmor.h>
+#include <linux/lsm/bpf.h>
struct linux_binprm;
struct cred;
@@ -140,6 +144,22 @@ enum lockdown_reason {
LOCKDOWN_CONFIDENTIALITY_MAX,
};
+/* scaffolding */
+struct lsmblob_scaffold {
+ u32 secid;
+};
+
+/*
+ * Data exported by the security modules
+ */
+struct lsmblob {
+ struct lsmblob_selinux selinux;
+ struct lsmblob_smack smack;
+ struct lsmblob_apparmor apparmor;
+ struct lsmblob_bpf bpf;
+ struct lsmblob_scaffold scaffold;
+};
+
extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
extern u32 lsm_active_cnt;
extern const struct lsm_id *lsm_idlist[];
--
2.41.0
Hi Casey,
On Sun, 2024-08-25 at 12:00 -0700, Casey Schaufler wrote:
> When more than one security module is exporting data to audit and
> networking sub-systems a single 32 bit integer is no longer
> sufficient to represent the data. Add a structure to be used instead.
>
> The lsmblob structure definition is intended to keep the LSM
> specific information private to the individual security modules.
> The module specific information is included in a new set of
> header files under include/lsm. Each security module is allowed
> to define the information included for its use in the lsmblob.
> SELinux includes a u32 secid. Smack includes a pointer into its
> global label list. The conditional compilation based on feature
> inclusion is contained in the include/lsm files.
>
> Suggested-by: Paul Moore <paul@paul-moore.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
> include/linux/lsm/apparmor.h | 17 +++++++++++++++++
> include/linux/lsm/bpf.h | 16 ++++++++++++++++
> include/linux/lsm/selinux.h | 16 ++++++++++++++++
> include/linux/lsm/smack.h | 17 +++++++++++++++++
> include/linux/security.h | 20 ++++++++++++++++++++
> 5 files changed, 86 insertions(+)
> create mode 100644 include/linux/lsm/apparmor.h
> create mode 100644 include/linux/lsm/bpf.h
> create mode 100644 include/linux/lsm/selinux.h
> create mode 100644 include/linux/lsm/smack.h
>
> diff --git a/include/linux/lsm/apparmor.h b/include/linux/lsm/apparmor.h
> new file mode 100644
> index 000000000000..8ff1cd899a20
> --- /dev/null
> +++ b/include/linux/lsm/apparmor.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Linux Security Module interface to other subsystems.
> + * AppArmor presents a single u32 value which is known as a secid.
Just a small nitpick: this comment doesn't match the code since it's
using aa_label instead of a u32 secid.
> + */
> +#ifndef __LINUX_LSM_APPARMOR_H
> +#define __LINUX_LSM_APPARMOR_H
> +
> +struct aa_label;
> +
> +struct lsmblob_apparmor {
> +#ifdef CONFIG_SECURITY_APPARMOR
> + struct aa_label *label;
> +#endif
> +};
> +
> +#endif /* ! __LINUX_LSM_APPARMOR_H */
> diff --git a/include/linux/lsm/bpf.h b/include/linux/lsm/bpf.h
> new file mode 100644
> index 000000000000..48abdcd82ded
> --- /dev/null
> +++ b/include/linux/lsm/bpf.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Linux Security Module interface to other subsystems.
> + * BPF may present a single u32 value.
> + */
> +#ifndef __LINUX_LSM_BPF_H
> +#define __LINUX_LSM_BPF_H
> +#include <linux/types.h>
> +
> +struct lsmblob_bpf {
> +#ifdef CONFIG_BPF_LSM
> + u32 secid;
> +#endif
> +};
> +
> +#endif /* ! __LINUX_LSM_BPF_H */
> diff --git a/include/linux/lsm/selinux.h b/include/linux/lsm/selinux.h
> new file mode 100644
> index 000000000000..fd16456b36ac
> --- /dev/null
> +++ b/include/linux/lsm/selinux.h
> @@ -0,0 +1,16 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Linux Security Module interface to other subsystems.
> + * SELinux presents a single u32 value which is known as a secid.
> + */
> +#ifndef __LINUX_LSM_SELINUX_H
> +#define __LINUX_LSM_SELINUX_H
> +#include <linux/types.h>
> +
> +struct lsmblob_selinux {
> +#ifdef CONFIG_SECURITY_SELINUX
> + u32 secid;
> +#endif
> +};
> +
> +#endif /* ! __LINUX_LSM_SELINUX_H */
> diff --git a/include/linux/lsm/smack.h b/include/linux/lsm/smack.h
> new file mode 100644
> index 000000000000..2018f288302f
> --- /dev/null
> +++ b/include/linux/lsm/smack.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Linux Security Module interface to other subsystems.
> + * Smack presents a pointer into the global Smack label list.
> + */
> +#ifndef __LINUX_LSM_SMACK_H
> +#define __LINUX_LSM_SMACK_H
> +
> +struct smack_known;
> +
> +struct lsmblob_smack {
> +#ifdef CONFIG_SECURITY_SMACK
> + struct smack_known *skp;
> +#endif
> +};
> +
> +#endif /* ! __LINUX_LSM_SMACK_H */
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 1390f1efb4f0..0057a22137e8 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -34,6 +34,10 @@
> #include <linux/sockptr.h>
> #include <linux/bpf.h>
> #include <uapi/linux/lsm.h>
> +#include <linux/lsm/selinux.h>
> +#include <linux/lsm/smack.h>
> +#include <linux/lsm/apparmor.h>
> +#include <linux/lsm/bpf.h>
>
> struct linux_binprm;
> struct cred;
> @@ -140,6 +144,22 @@ enum lockdown_reason {
> LOCKDOWN_CONFIDENTIALITY_MAX,
> };
>
> +/* scaffolding */
> +struct lsmblob_scaffold {
> + u32 secid;
> +};
> +
> +/*
> + * Data exported by the security modules
> + */
> +struct lsmblob {
> + struct lsmblob_selinux selinux;
> + struct lsmblob_smack smack;
> + struct lsmblob_apparmor apparmor;
> + struct lsmblob_bpf bpf;
> + struct lsmblob_scaffold scaffold;
> +};
> +
> extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
> extern u32 lsm_active_cnt;
> extern const struct lsm_id *lsm_idlist[];
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