diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | include/linux/security.h | 12 | ||||
| -rw-r--r-- | security/dummy.c | 4 | ||||
| -rw-r--r-- | security/security.c | 38 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 7 | ||||
| -rw-r--r-- | security/smack/smack.h | 2 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 7 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 11 |
8 files changed, 83 insertions, 4 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 256a2162503c..4b0f1ae31a4c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -366,6 +366,12 @@ and is between 256 and 4096 characters. It is defined in the file possible to determine what the correct size should be. This option provides an override for these situations. + security= [SECURITY] Choose a security module to enable at boot. + If this boot parameter is not specified, only the first + security module asking for security registration will be + loaded. An invalid security module name will be treated + as if no module has been chosen. + capability.disable= [SECURITY] Disable capabilities. This would normally be used only if an alternative security model is to be diff --git a/include/linux/security.h b/include/linux/security.h index 697f228daf19..f4116d6ed64b 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -36,6 +36,9 @@ extern unsigned securebits; +/* Maximum number of letters for an LSM name string */ +#define SECURITY_NAME_MAX 10 + struct ctl_table; struct audit_krule; @@ -137,6 +140,12 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) /** * struct security_operations - main security structure * + * Security module identifier. + * + * @name: + * A string that acts as a unique identifeir for the LSM with max number + * of characters = SECURITY_NAME_MAX. + * * Security hooks for program execution operations. * * @bprm_alloc_security: @@ -1270,6 +1279,8 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * This is the main security structure. */ struct security_operations { + char name[SECURITY_NAME_MAX + 1]; + int (*ptrace) (struct task_struct * parent, struct task_struct * child); int (*capget) (struct task_struct * target, kernel_cap_t * effective, @@ -1537,6 +1548,7 @@ struct security_operations { /* prototypes */ extern int security_init (void); +extern int security_module_enable(struct security_operations *ops); extern int register_security (struct security_operations *ops); extern int mod_reg_security (const char *name, struct security_operations *ops); extern struct dentry *securityfs_create_file(const char *name, mode_t mode, diff --git a/security/dummy.c b/security/dummy.c index 1ac9f8e66aa2..d797a4196b89 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -1017,7 +1017,9 @@ static inline void dummy_audit_rule_free(void *lsmrule) #endif /* CONFIG_AUDIT */ -struct security_operations dummy_security_ops; +struct security_operations dummy_security_ops = { + .name = "dummy", +}; #define set_to_dummy_if_null(ops, function) \ do { \ diff --git a/security/security.c b/security/security.c index 2ef593ec70f3..dd0c6baed494 100644 --- a/security/security.c +++ b/security/security.c @@ -17,6 +17,8 @@ #include <linux/kernel.h> #include <linux/security.h> +/* Boot-time LSM user choice */ +static __initdata char chosen_lsm[SECURITY_NAME_MAX + 1]; /* things that live in dummy.c */ extern struct security_operations dummy_security_ops; @@ -67,13 +69,47 @@ int __init security_init(void) return 0; } +/* Save user chosen LSM */ +static int __init choose_lsm(char *str) +{ + strncpy(chosen_lsm, str, SECURITY_NAME_MAX); + return 1; +} +__setup("security=", choose_lsm); + +/** + * security_module_enable - Load given security module on boot ? + * @ops: a pointer to the struct security_operations that is to be checked. + * + * Each LSM must pass this method before registering its own operations + * to avoid security registration races. This method may also be used + * to check if your LSM is currently loaded. + * + * Return true if: + * -The passed LSM is the one chosen by user at boot time, + * -or user didsn't specify a specific LSM and we're the first to ask + * for registeration permissoin, + * -or the passed LSM is currently loaded. + * Otherwise, return false. + */ +int __init security_module_enable(struct security_operations *ops) +{ + if (!*chosen_lsm) + strncpy(chosen_lsm, ops->name, SECURITY_NAME_MAX); + else if (strncmp(ops->name, chosen_lsm, SECURITY_NAME_MAX)) + return 0; + + return 1; +} + /** * register_security - registers a security framework with the kernel * @ops: a pointer to the struct security_options that is to be registered * * This function is to allow a security module to register itself with the * kernel security subsystem. Some rudimentary checking is done on the @ops - * value passed to this function. + * value passed to this function. You'll need to check first if your LSM + * is allowed to register its @ops by calling security_module_enable(@ops). * * If there is already a security module registered with the kernel, * an error will be returned. Otherwise 0 is returned on success. diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a2f7e9cf78c5..f9927f02bc3d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5295,6 +5295,8 @@ static int selinux_key_permission(key_ref_t key_ref, #endif static struct security_operations selinux_ops = { + .name = "selinux", + .ptrace = selinux_ptrace, .capget = selinux_capget, .capset_check = selinux_capset_check, @@ -5492,6 +5494,11 @@ static __init int selinux_init(void) { struct task_security_struct *tsec; + if (!security_module_enable(&selinux_ops)) { + selinux_enabled = 0; + return 0; + } + if (!selinux_enabled) { printk(KERN_INFO "SELinux: Disabled at boot.\n"); return 0; diff --git a/security/smack/smack.h b/security/smack/smack.h index 62c1e982849d..4a4477f5afdc 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -15,6 +15,7 @@ #include <linux/capability.h> #include <linux/spinlock.h> +#include <linux/security.h> #include <net/netlabel.h> /* @@ -187,6 +188,7 @@ extern struct smack_known smack_known_star; extern struct smack_known smack_known_unset; extern struct smk_list_entry *smack_list; +extern struct security_operations smack_ops; /* * Stricly for CIPSO level manipulation. diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 732ba27923c4..904bdc01a12b 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -2424,7 +2424,9 @@ static void smack_release_secctx(char *secdata, u32 seclen) { } -static struct security_operations smack_ops = { +struct security_operations smack_ops = { + .name = "smack", + .ptrace = smack_ptrace, .capget = cap_capget, .capset_check = cap_capset_check, @@ -2557,6 +2559,9 @@ static struct security_operations smack_ops = { */ static __init int smack_init(void) { + if (!security_module_enable(&smack_ops)) + return 0; + printk(KERN_INFO "Smack: Initializing.\n"); /* diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index cfae8afcc262..6ba283783b70 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -965,12 +965,21 @@ static struct vfsmount *smackfs_mount; * * register the smackfs * - * Returns 0 unless the registration fails. + * Do not register smackfs if Smack wasn't enabled + * on boot. We can not put this method normally under the + * smack_init() code path since the security subsystem get + * initialized before the vfs caches. + * + * Returns true if we were not chosen on boot or if + * we were chosen and filesystem registration succeeded. */ static int __init init_smk_fs(void) { int err; + if (!security_module_enable(&smack_ops)) + return 0; + err = register_filesystem(&smk_fs_type); if (!err) { smackfs_mount = kern_mount(&smk_fs_type); |