Create a new domain.h file containing the struct landlock_hierarchy definition and helpers. This type will grow with audit support. This also prepares for a new domain type.
Export landlock_get_hierarchy() and landlock_put_hierarchy() that will be used by audit in a following commit. Clean up Makefile entries. Cc: Günther Noack <[email protected]> Signed-off-by: Mickaël Salaün <[email protected]> Link: https://lore.kernel.org/r/[email protected] --- Changes since v3: - Export landlock_get_hierarchy() and landlock_put_hierarchy(). - Clean up Makefile entries. Changes since v1: - New patch. --- MAINTAINERS | 1 + include/linux/landlock.h | 31 +++++++++++++++++++++++++++++++ security/landlock/Makefile | 11 +++++++++-- security/landlock/domain.c | 29 +++++++++++++++++++++++++++++ security/landlock/domain.h | 31 +++++++++++++++++++++++++++++++ security/landlock/ruleset.c | 22 ++++------------------ security/landlock/ruleset.h | 17 +---------------- security/landlock/task.c | 1 + 8 files changed, 107 insertions(+), 36 deletions(-) create mode 100644 include/linux/landlock.h create mode 100644 security/landlock/domain.c create mode 100644 security/landlock/domain.h diff --git a/MAINTAINERS b/MAINTAINERS index 30cbc3d44cd5..425676b25a4f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12961,6 +12961,7 @@ T: git https://git.kernel.org/pub/scm/linux/kernel/git/mic/linux.git F: Documentation/security/landlock.rst F: Documentation/userspace-api/landlock.rst F: fs/ioctl.c +F: include/linux/landlock.h F: include/uapi/linux/landlock.h F: samples/landlock/ F: security/landlock/ diff --git a/include/linux/landlock.h b/include/linux/landlock.h new file mode 100644 index 000000000000..8491142658a1 --- /dev/null +++ b/include/linux/landlock.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Landlock - Kernel API + * + * Copyright © 2024-2025 Microsoft Corporation + */ + +#ifndef _LINUX_LANDLOCK_H +#define _LINUX_LANDLOCK_H + +struct landlock_hierarchy; + +#ifdef CONFIG_SECURITY_LANDLOCK + +void landlock_get_hierarchy(struct landlock_hierarchy *hierarchy); + +void landlock_put_hierarchy(struct landlock_hierarchy *hierarchy); + +#else /* CONFIG_SECURITY_LANDLOCK */ + +static inline void landlock_get_hierarchy(struct landlock_hierarchy *hierarchy) +{ +} + +static inline void landlock_put_hierarchy(struct landlock_hierarchy *hierarchy) +{ +} + +#endif /* CONFIG_SECURITY_LANDLOCK */ + +#endif /* _LINUX_LANDLOCK_H */ diff --git a/security/landlock/Makefile b/security/landlock/Makefile index e1777abbc413..51815908a464 100644 --- a/security/landlock/Makefile +++ b/security/landlock/Makefile @@ -1,7 +1,14 @@ obj-$(CONFIG_SECURITY_LANDLOCK) := landlock.o -landlock-y := setup.o syscalls.o object.o ruleset.o \ - cred.o task.o fs.o +landlock-y := \ + setup.o \ + syscalls.o \ + object.o \ + ruleset.o \ + cred.o \ + task.o \ + fs.o \ + domain.o landlock-$(CONFIG_INET) += net.o diff --git a/security/landlock/domain.c b/security/landlock/domain.c new file mode 100644 index 000000000000..df58638ffc50 --- /dev/null +++ b/security/landlock/domain.c @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Landlock LSM - Domain management + * + * Copyright © 2016-2020 Mickaël Salaün <[email protected]> + * Copyright © 2018-2020 ANSSI + * Copyright © 2024-2025 Microsoft Corporation + */ + +#include <linux/landlock.h> +#include <linux/mm.h> + +#include "domain.h" + +void landlock_get_hierarchy(struct landlock_hierarchy *const hierarchy) +{ + if (hierarchy) + refcount_inc(&hierarchy->usage); +} + +void landlock_put_hierarchy(struct landlock_hierarchy *hierarchy) +{ + while (hierarchy && refcount_dec_and_test(&hierarchy->usage)) { + const struct landlock_hierarchy *const freeme = hierarchy; + + hierarchy = hierarchy->parent; + kfree(freeme); + } +} diff --git a/security/landlock/domain.h b/security/landlock/domain.h new file mode 100644 index 000000000000..2e612ef754e3 --- /dev/null +++ b/security/landlock/domain.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Landlock LSM - Domain management + * + * Copyright © 2016-2020 Mickaël Salaün <[email protected]> + * Copyright © 2018-2020 ANSSI + */ + +#ifndef _SECURITY_LANDLOCK_DOMAIN_H +#define _SECURITY_LANDLOCK_DOMAIN_H + +#include <linux/landlock.h> +#include <linux/refcount.h> + +/** + * struct landlock_hierarchy - Node in a domain hierarchy + */ +struct landlock_hierarchy { + /** + * @parent: Pointer to the parent node, or NULL if it is a root + * Landlock domain. + */ + struct landlock_hierarchy *parent; + /** + * @usage: Number of potential children domains plus their parent + * domain. + */ + refcount_t usage; +}; + +#endif /* _SECURITY_LANDLOCK_DOMAIN_H */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index dbc528f5f3b7..8b47af69af3e 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -12,6 +12,7 @@ #include <linux/err.h> #include <linux/errno.h> #include <linux/kernel.h> +#include <linux/landlock.h> #include <linux/lockdep.h> #include <linux/overflow.h> #include <linux/rbtree.h> @@ -21,6 +22,7 @@ #include <linux/workqueue.h> #include "access.h" +#include "domain.h" #include "limits.h" #include "object.h" #include "ruleset.h" @@ -305,22 +307,6 @@ int landlock_insert_rule(struct landlock_ruleset *const ruleset, return insert_rule(ruleset, id, &layers, ARRAY_SIZE(layers)); } -static void get_hierarchy(struct landlock_hierarchy *const hierarchy) -{ - if (hierarchy) - refcount_inc(&hierarchy->usage); -} - -static void put_hierarchy(struct landlock_hierarchy *hierarchy) -{ - while (hierarchy && refcount_dec_and_test(&hierarchy->usage)) { - const struct landlock_hierarchy *const freeme = hierarchy; - - hierarchy = hierarchy->parent; - kfree(freeme); - } -} - static int merge_tree(struct landlock_ruleset *const dst, struct landlock_ruleset *const src, const enum landlock_key_type key_type) @@ -475,7 +461,7 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, err = -EINVAL; goto out_unlock; } - get_hierarchy(parent->hierarchy); + landlock_get_hierarchy(parent->hierarchy); child->hierarchy->parent = parent->hierarchy; out_unlock: @@ -499,7 +485,7 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) free_rule(freeme, LANDLOCK_KEY_NET_PORT); #endif /* IS_ENABLED(CONFIG_INET) */ - put_hierarchy(ruleset->hierarchy); + landlock_put_hierarchy(ruleset->hierarchy); kfree(ruleset); } diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index 2f29b9f40392..39169b6860e3 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -15,6 +15,7 @@ #include <linux/workqueue.h> #include "access.h" +#include "domain.h" #include "limits.h" #include "object.h" @@ -106,22 +107,6 @@ struct landlock_rule { struct landlock_layer layers[] __counted_by(num_layers); }; -/** - * struct landlock_hierarchy - Node in a ruleset hierarchy - */ -struct landlock_hierarchy { - /** - * @parent: Pointer to the parent node, or NULL if it is a root - * Landlock domain. - */ - struct landlock_hierarchy *parent; - /** - * @usage: Number of potential children domains plus their parent - * domain. - */ - refcount_t usage; -}; - /** * struct landlock_ruleset - Landlock ruleset * diff --git a/security/landlock/task.c b/security/landlock/task.c index dc7dab78392e..98894ad1abc7 100644 --- a/security/landlock/task.c +++ b/security/landlock/task.c @@ -18,6 +18,7 @@ #include "common.h" #include "cred.h" +#include "domain.h" #include "fs.h" #include "ruleset.h" #include "setup.h" -- 2.47.1
