| Message ID | 20230802174435.11928-3-casey@schaufler-ca.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | LSM: Three basic syscalls | expand |
On 8/2/23 10:44, Casey Schaufler wrote: > As LSMs are registered add their lsm_id pointers to a table. > This will be used later for attribute reporting. > > Determine the number of possible security modules based on > their respective CONFIG options. This allows the number to be > known at build time. This allows data structures and tables > to use the constant. > > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > Reviewed-by: Serge Hallyn <serge@hallyn.com> Reviewed-by: John Johansen <john.johansen@canonical.com> > --- > include/linux/security.h | 2 ++ > security/security.c | 37 +++++++++++++++++++++++++++++++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/include/linux/security.h b/include/linux/security.h > index 32828502f09e..a20a4ceda6d9 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -138,6 +138,8 @@ enum lockdown_reason { > }; > > extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; > +extern u32 lsm_active_cnt; > +extern const struct lsm_id *lsm_idlist[]; > > /* These functions are in security/commoncap.c */ > extern int cap_capable(const struct cred *cred, struct user_namespace *ns, > diff --git a/security/security.c b/security/security.c > index feaae09581dc..87b70a55a028 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -36,6 +36,25 @@ > /* How many LSMs were built into the kernel? */ > #define LSM_COUNT (__end_lsm_info - __start_lsm_info) > > +/* > + * How many LSMs are built into the kernel as determined at > + * build time. Used to determine fixed array sizes. > + * The capability module is accounted for by CONFIG_SECURITY > + */ > +#define LSM_CONFIG_COUNT ( \ > + (IS_ENABLED(CONFIG_SECURITY) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_IMA) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0)) > + > /* > * These are descriptions of the reasons that can be passed to the > * security_locked_down() LSM hook. Placing this array here allows > @@ -245,6 +264,12 @@ static void __init initialize_lsm(struct lsm_info *lsm) > } > } > > +/* > + * Current index to use while initializing the lsm id list. > + */ > +u32 lsm_active_cnt __ro_after_init; > +const struct lsm_id *lsm_idlist[LSM_CONFIG_COUNT] __ro_after_init; > + > /* Populate ordered LSMs list from comma-separated LSM name list. */ > static void __init ordered_lsm_parse(const char *order, const char *origin) > { > @@ -521,6 +546,18 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, > { > int i; > > + /* > + * A security module may call security_add_hooks() more > + * than once during initialization, and LSM initialization > + * is serialized. Landlock is one such case. > + * Look at the previous entry, if there is one, for duplication. > + */ > + if (lsm_active_cnt == 0 || lsm_idlist[lsm_active_cnt - 1] != lsmid) { > + if (lsm_active_cnt >= LSM_CONFIG_COUNT) > + panic("%s Too many LSMs registered.\n", __func__); > + lsm_idlist[lsm_active_cnt++] = lsmid; > + } > + > for (i = 0; i < count; i++) { > hooks[i].lsmid = lsmid; > hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
On Wed, Aug 02, 2023 at 10:44:25AM -0700, Casey Schaufler wrote: > As LSMs are registered add their lsm_id pointers to a table. > This will be used later for attribute reporting. > > Determine the number of possible security modules based on > their respective CONFIG options. This allows the number to be > known at build time. This allows data structures and tables > to use the constant. > > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> > Reviewed-by: Kees Cook <keescook@chromium.org> > Reviewed-by: Serge Hallyn <serge@hallyn.com> > --- > include/linux/security.h | 2 ++ > security/security.c | 37 +++++++++++++++++++++++++++++++++++++ > 2 files changed, 39 insertions(+) > > diff --git a/include/linux/security.h b/include/linux/security.h > index 32828502f09e..a20a4ceda6d9 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -138,6 +138,8 @@ enum lockdown_reason { > }; > > extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; > +extern u32 lsm_active_cnt; > +extern const struct lsm_id *lsm_idlist[]; > > /* These functions are in security/commoncap.c */ > extern int cap_capable(const struct cred *cred, struct user_namespace *ns, > diff --git a/security/security.c b/security/security.c > index feaae09581dc..87b70a55a028 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -36,6 +36,25 @@ > /* How many LSMs were built into the kernel? */ > #define LSM_COUNT (__end_lsm_info - __start_lsm_info) > > +/* > + * How many LSMs are built into the kernel as determined at > + * build time. Used to determine fixed array sizes. > + * The capability module is accounted for by CONFIG_SECURITY > + */ > +#define LSM_CONFIG_COUNT ( \ > + (IS_ENABLED(CONFIG_SECURITY) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_IMA) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \ > + (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0)) > + > /* > * These are descriptions of the reasons that can be passed to the > * security_locked_down() LSM hook. Placing this array here allows > @@ -245,6 +264,12 @@ static void __init initialize_lsm(struct lsm_info *lsm) > } > } > > +/* > + * Current index to use while initializing the lsm id list. > + */ > +u32 lsm_active_cnt __ro_after_init; > +const struct lsm_id *lsm_idlist[LSM_CONFIG_COUNT] __ro_after_init; I guess __ro_after_init is superfluous here. Reviewed-by: Mickaël Salaün <mic@digikod.net> > + > /* Populate ordered LSMs list from comma-separated LSM name list. */ > static void __init ordered_lsm_parse(const char *order, const char *origin) > { > @@ -521,6 +546,18 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, > { > int i; > > + /* > + * A security module may call security_add_hooks() more > + * than once during initialization, and LSM initialization > + * is serialized. Landlock is one such case. > + * Look at the previous entry, if there is one, for duplication. > + */ > + if (lsm_active_cnt == 0 || lsm_idlist[lsm_active_cnt - 1] != lsmid) { > + if (lsm_active_cnt >= LSM_CONFIG_COUNT) > + panic("%s Too many LSMs registered.\n", __func__); > + lsm_idlist[lsm_active_cnt++] = lsmid; > + } > + > for (i = 0; i < count; i++) { > hooks[i].lsmid = lsmid; > hlist_add_tail_rcu(&hooks[i].list, hooks[i].head); > -- > 2.41.0 >
diff --git a/include/linux/security.h b/include/linux/security.h index 32828502f09e..a20a4ceda6d9 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -138,6 +138,8 @@ enum lockdown_reason { }; extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1]; +extern u32 lsm_active_cnt; +extern const struct lsm_id *lsm_idlist[]; /* These functions are in security/commoncap.c */ extern int cap_capable(const struct cred *cred, struct user_namespace *ns, diff --git a/security/security.c b/security/security.c index feaae09581dc..87b70a55a028 100644 --- a/security/security.c +++ b/security/security.c @@ -36,6 +36,25 @@ /* How many LSMs were built into the kernel? */ #define LSM_COUNT (__end_lsm_info - __start_lsm_info) +/* + * How many LSMs are built into the kernel as determined at + * build time. Used to determine fixed array sizes. + * The capability module is accounted for by CONFIG_SECURITY + */ +#define LSM_CONFIG_COUNT ( \ + (IS_ENABLED(CONFIG_SECURITY) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_TOMOYO) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_IMA) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_YAMA) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_LOADPIN) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_SAFESETID) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_LOCKDOWN_LSM) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0) + \ + (IS_ENABLED(CONFIG_SECURITY_LANDLOCK) ? 1 : 0)) + /* * These are descriptions of the reasons that can be passed to the * security_locked_down() LSM hook. Placing this array here allows @@ -245,6 +264,12 @@ static void __init initialize_lsm(struct lsm_info *lsm) } } +/* + * Current index to use while initializing the lsm id list. + */ +u32 lsm_active_cnt __ro_after_init; +const struct lsm_id *lsm_idlist[LSM_CONFIG_COUNT] __ro_after_init; + /* Populate ordered LSMs list from comma-separated LSM name list. */ static void __init ordered_lsm_parse(const char *order, const char *origin) { @@ -521,6 +546,18 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count, { int i; + /* + * A security module may call security_add_hooks() more + * than once during initialization, and LSM initialization + * is serialized. Landlock is one such case. + * Look at the previous entry, if there is one, for duplication. + */ + if (lsm_active_cnt == 0 || lsm_idlist[lsm_active_cnt - 1] != lsmid) { + if (lsm_active_cnt >= LSM_CONFIG_COUNT) + panic("%s Too many LSMs registered.\n", __func__); + lsm_idlist[lsm_active_cnt++] = lsmid; + } + for (i = 0; i < count; i++) { hooks[i].lsmid = lsmid; hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);