apparmor: move resource checks to using labels

Signed-off-by: John Johansen <john.johansen@canonical.com>

3 files changed, 80 insertions, 42 deletions

diff --git a/security/apparmor/include/resource.h b/security/apparmor/include/resource.h
index f6289f335c4d..76f1586c9adb 100644
--- a/security/apparmor/include/resource.h
+++ b/security/apparmor/include/resource.h
@@ -37,10 +37,10 @@ struct aa_rlimit {
 extern struct aa_sfs_entry aa_sfs_entry_rlimit[];
 
 int aa_map_resource(int resource);
-int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *,
+int aa_task_setrlimit(struct aa_label *label, struct task_struct *task,
                       unsigned int resource, struct rlimit *new_rlim);
 
-void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new);
+void __aa_transition_rlimits(struct aa_label *old, struct aa_label *new);
 
 static inline void aa_free_rlimit_rules(struct aa_rlimit *rlims)
 {
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index bcfdcdb3eae2..c3e98f74268f 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -625,8 +625,7 @@ static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
         current->pdeath_signal = 0;
 
         /* reset soft limits and set hard limits for the new label */
-        __aa_transition_rlimits(labels_profile(label),
-                                labels_profile(new_ctx->label));
+        __aa_transition_rlimits(label, new_ctx->label);
 }
 
 /**
@@ -646,8 +645,7 @@ static int apparmor_task_setrlimit(struct task_struct *task,
         int error = 0;
 
         if (!unconfined(label))
-                error = aa_task_setrlimit(labels_profile(label), task,
-                                          resource, new_rlim);
+                error = aa_task_setrlimit(label, task, resource, new_rlim);
         __end_current_label_crit_section(label);
 
         return error;
diff --git a/security/apparmor/resource.c b/security/apparmor/resource.c
index 2474ee0b3467..d8bc842594ed 100644
--- a/security/apparmor/resource.c
+++ b/security/apparmor/resource.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/audit.h>
+#include <linux/security.h>
 
 #include "include/audit.h"
 #include "include/context.h"
@@ -36,6 +37,11 @@ static void audit_cb(struct audit_buffer *ab, void *va)
 
         audit_log_format(ab, " rlimit=%s value=%lu",
                          rlim_names[aad(sa)->rlim.rlim], aad(sa)->rlim.max);
+        if (aad(sa)->peer) {
+                audit_log_format(ab, " peer=");
+                aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
+                                FLAGS_NONE, GFP_ATOMIC);
+        }
 }
 
 /**
@@ -48,13 +54,17 @@ static void audit_cb(struct audit_buffer *ab, void *va)
  * Returns: 0 or sa->error else other error code on failure
  */
 static int audit_resource(struct aa_profile *profile, unsigned int resource,
-                          unsigned long value, int error)
+                          unsigned long value, struct aa_label *peer,
+                          const char *info, int error)
 {
         DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SETRLIMIT);
 
         aad(&sa)->rlim.rlim = resource;
         aad(&sa)->rlim.max = value;
+        aad(&sa)->peer = peer;
+        aad(&sa)->info = info;
         aad(&sa)->error = error;
+
         return aa_audit(AUDIT_APPARMOR_AUTO, profile, &sa, audit_cb);
 }
 
@@ -72,9 +82,21 @@ int aa_map_resource(int resource)
         return rlim_map[resource];
 }
 
+static int profile_setrlimit(struct aa_profile *profile, unsigned int resource,
+                             struct rlimit *new_rlim)
+{
+        int e = 0;
+
+        if (profile->rlimits.mask & (1 << resource) && new_rlim->rlim_max >
+            profile->rlimits.limits[resource].rlim_max)
+                e = -EACCES;
+        return audit_resource(profile, resource, new_rlim->rlim_max, NULL, NULL,
+                              e);
+}
+
 /**
  * aa_task_setrlimit - test permission to set an rlimit
- * @profile - profile confining the task  (NOT NULL)
+ * @label - label confining the task  (NOT NULL)
  * @task - task the resource is being set on
  * @resource - the resource being set
  * @new_rlim - the new resource limit  (NOT NULL)
@@ -83,14 +105,15 @@ int aa_map_resource(int resource)
  *
  * Returns: 0 or error code if setting resource failed
  */
-int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task,
+int aa_task_setrlimit(struct aa_label *label, struct task_struct *task,
                       unsigned int resource, struct rlimit *new_rlim)
 {
-        struct aa_label *task_label;
+        struct aa_profile *profile;
+        struct aa_label *peer;
         int error = 0;
 
         rcu_read_lock();
-        task_label = aa_get_newest_cred_label((__task_cred(task)));
+        peer = aa_get_newest_cred_label(__task_cred(task));
         rcu_read_unlock();
 
         /* TODO: extend resource control to handle other (non current)
@@ -99,53 +122,70 @@ int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task,
          * the same profile or that the task setting the resource of another
          * task has CAP_SYS_RESOURCE.
          */
-        if ((profile != labels_profile(task_label) &&
-             aa_capable(&profile->label, CAP_SYS_RESOURCE, 1)) ||
-            (profile->rlimits.mask & (1 << resource) &&
-             new_rlim->rlim_max > profile->rlimits.limits[resource].rlim_max))
-                error = -EACCES;
 
-        aa_put_label(task_label);
-
-        return audit_resource(profile, resource, new_rlim->rlim_max, error);
+        if (label != peer &&
+            !aa_capable(label, CAP_SYS_RESOURCE, SECURITY_CAP_NOAUDIT))
+                error = fn_for_each(label, profile,
+                                audit_resource(profile, resource,
+                                               new_rlim->rlim_max, peer,
+                                               "cap_sys_resoure", -EACCES));
+        else
+                error = fn_for_each_confined(label, profile,
+                                profile_setrlimit(profile, resource, new_rlim));
+        aa_put_label(peer);
+
+        return error;
 }
 
 /**
  * __aa_transition_rlimits - apply new profile rlimits
- * @old: old profile on task  (NOT NULL)
- * @new: new profile with rlimits to apply  (NOT NULL)
+ * @old_l: old label on task  (NOT NULL)
+ * @new_l: new label with rlimits to apply  (NOT NULL)
  */
-void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new)
+void __aa_transition_rlimits(struct aa_label *old_l, struct aa_label *new_l)
 {
         unsigned int mask = 0;
         struct rlimit *rlim, *initrlim;
-        int i;
+        struct aa_profile *old, *new;
+        struct label_it i;
+
+        old = labels_profile(old_l);
+        new = labels_profile(new_l);
 
-        /* for any rlimits the profile controlled reset the soft limit
-         * to the less of the tasks hard limit and the init tasks soft limit
+        /* for any rlimits the profile controlled, reset the soft limit
+         * to the lesser of the tasks hard limit and the init tasks soft limit
          */
-        if (old->rlimits.mask) {
-                for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
-                        if (old->rlimits.mask & mask) {
-                                rlim = current->signal->rlim + i;
-                                initrlim = init_task.signal->rlim + i;
-                                rlim->rlim_cur = min(rlim->rlim_max,
-                                                     initrlim->rlim_cur);
+        label_for_each_confined(i, old_l, old) {
+                if (old->rlimits.mask) {
+                        int j;
+
+                        for (j = 0, mask = 1; j < RLIM_NLIMITS; j++,
+                                     mask <<= 1) {
+                                if (old->rlimits.mask & mask) {
+                                        rlim = current->signal->rlim + j;
+                                        initrlim = init_task.signal->rlim + j;
+                                        rlim->rlim_cur = min(rlim->rlim_max,
+                                                            initrlim->rlim_cur);
+                                }
                         }
                 }
         }
 
         /* set any new hard limits as dictated by the new profile */
-        if (!new->rlimits.mask)
-                return;
-        for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
-                if (!(new->rlimits.mask & mask))
-                        continue;
+        label_for_each_confined(i, new_l, new) {
+                int j;
 
-                rlim = current->signal->rlim + i;
-                rlim->rlim_max = min(rlim->rlim_max,
-                                     new->rlimits.limits[i].rlim_max);
-                /* soft limit should not exceed hard limit */
-                rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);
+                if (!new->rlimits.mask)
+                        continue;
+                for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, mask <<= 1) {
+                        if (!(new->rlimits.mask & mask))
+                                continue;
+
+                        rlim = current->signal->rlim + j;
+                        rlim->rlim_max = min(rlim->rlim_max,
+                                             new->rlimits.limits[j].rlim_max);
+                        /* soft limit should not exceed hard limit */
+                        rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);
+                }
         }
 }