CRED: Neuter sys_capset()
[safe/jmp/linux-2.6] / kernel / capability.c
index adb262f..58b0051 100644 (file)
@@ -127,160 +127,6 @@ static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy)
        return 0;
 }
 
-#ifndef CONFIG_SECURITY_FILE_CAPABILITIES
-
-/*
- * Without filesystem capability support, we nominally support one process
- * setting the capabilities of another
- */
-static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
-                                    kernel_cap_t *pIp, kernel_cap_t *pPp)
-{
-       struct task_struct *target;
-       int ret;
-
-       spin_lock(&task_capability_lock);
-       read_lock(&tasklist_lock);
-
-       if (pid && pid != task_pid_vnr(current)) {
-               target = find_task_by_vpid(pid);
-               if (!target) {
-                       ret = -ESRCH;
-                       goto out;
-               }
-       } else
-               target = current;
-
-       ret = security_capget(target, pEp, pIp, pPp);
-
-out:
-       read_unlock(&tasklist_lock);
-       spin_unlock(&task_capability_lock);
-
-       return ret;
-}
-
-/*
- * cap_set_pg - set capabilities for all processes in a given process
- * group.  We call this holding task_capability_lock and tasklist_lock.
- */
-static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective,
-                            kernel_cap_t *inheritable,
-                            kernel_cap_t *permitted)
-{
-       struct task_struct *g, *target;
-       int ret = -EPERM;
-       int found = 0;
-       struct pid *pgrp;
-
-       spin_lock(&task_capability_lock);
-       read_lock(&tasklist_lock);
-
-       pgrp = find_vpid(pgrp_nr);
-       do_each_pid_task(pgrp, PIDTYPE_PGID, g) {
-               target = g;
-               while_each_thread(g, target) {
-                       if (!security_capset_check(target, effective,
-                                                  inheritable, permitted)) {
-                               security_capset_set(target, effective,
-                                                   inheritable, permitted);
-                               ret = 0;
-                       }
-                       found = 1;
-               }
-       } while_each_pid_task(pgrp, PIDTYPE_PGID, g);
-
-       read_unlock(&tasklist_lock);
-       spin_unlock(&task_capability_lock);
-
-       if (!found)
-               ret = 0;
-       return ret;
-}
-
-/*
- * cap_set_all - set capabilities for all processes other than init
- * and self.  We call this holding task_capability_lock and tasklist_lock.
- */
-static inline int cap_set_all(kernel_cap_t *effective,
-                             kernel_cap_t *inheritable,
-                             kernel_cap_t *permitted)
-{
-       struct task_struct *g, *target;
-       int ret = -EPERM;
-       int found = 0;
-
-       spin_lock(&task_capability_lock);
-       read_lock(&tasklist_lock);
-
-       do_each_thread(g, target) {
-               if (target == current
-                   || is_container_init(target->group_leader))
-                       continue;
-               found = 1;
-               if (security_capset_check(target, effective, inheritable,
-                                         permitted))
-                       continue;
-               ret = 0;
-               security_capset_set(target, effective, inheritable, permitted);
-       } while_each_thread(g, target);
-
-       read_unlock(&tasklist_lock);
-       spin_unlock(&task_capability_lock);
-
-       if (!found)
-               ret = 0;
-
-       return ret;
-}
-
-/*
- * Given the target pid does not refer to the current process we
- * need more elaborate support... (This support is not present when
- * filesystem capabilities are configured.)
- */
-static inline int do_sys_capset_other_tasks(pid_t pid, kernel_cap_t *effective,
-                                           kernel_cap_t *inheritable,
-                                           kernel_cap_t *permitted)
-{
-       struct task_struct *target;
-       int ret;
-
-       if (!capable(CAP_SETPCAP))
-               return -EPERM;
-
-       if (pid == -1)            /* all procs other than current and init */
-               return cap_set_all(effective, inheritable, permitted);
-
-       else if (pid < 0)                    /* all procs in process group */
-               return cap_set_pg(-pid, effective, inheritable, permitted);
-
-       /* target != current */
-       spin_lock(&task_capability_lock);
-       read_lock(&tasklist_lock);
-
-       target = find_task_by_vpid(pid);
-       if (!target)
-               ret = -ESRCH;
-       else {
-               ret = security_capset_check(target, effective, inheritable,
-                                           permitted);
-
-               /* having verified that the proposed changes are legal,
-                  we now put them into effect. */
-               if (!ret)
-                       security_capset_set(target, effective, inheritable,
-                                           permitted);
-       }
-
-       read_unlock(&tasklist_lock);
-       spin_unlock(&task_capability_lock);
-
-       return ret;
-}
-
-#else /* ie., def CONFIG_SECURITY_FILE_CAPABILITIES */
-
 /*
  * If we have configured with filesystem capability support, then the
  * only thing that can change the capabilities of the current process
@@ -315,22 +161,6 @@ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
 }
 
 /*
- * With filesystem capability support configured, the kernel does not
- * permit the changing of capabilities in one process by another
- * process. (CAP_SETPCAP has much less broad semantics when configured
- * this way.)
- */
-static inline int do_sys_capset_other_tasks(pid_t pid,
-                                           kernel_cap_t *effective,
-                                           kernel_cap_t *inheritable,
-                                           kernel_cap_t *permitted)
-{
-       return -EPERM;
-}
-
-#endif /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */
-
-/*
  * Atomically modify the effective capabilities returning the original
  * value. No permission check is performed here - it is assumed that the
  * caller is permitted to set the desired effective capabilities.
@@ -424,16 +254,14 @@ asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
  * @data: pointer to struct that contains the effective, permitted,
  *     and inheritable capabilities
  *
- * Set capabilities for a given process, all processes, or all
- * processes in a given process group.
+ * Set capabilities for the current process only.  The ability to any other
+ * process(es) has been deprecated and removed.
  *
  * The restrictions on setting capabilities are specified as:
  *
- * [pid is for the 'target' task.  'current' is the calling task.]
- *
- * I: any raised capabilities must be a subset of the (old current) permitted
- * P: any raised capabilities must be a subset of the (old current) permitted
- * E: must be set to a subset of (new target) permitted
+ * I: any raised capabilities must be a subset of the old permitted
+ * P: any raised capabilities must be a subset of the old permitted
+ * E: must be set to a subset of new permitted
  *
  * Returns 0 on success and < 0 on error.
  */
@@ -452,10 +280,13 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
        if (get_user(pid, &header->pid))
                return -EFAULT;
 
+       /* may only affect current now */
+       if (pid != 0 && pid != task_pid_vnr(current))
+               return -EPERM;
+
        if (copy_from_user(&kdata, data, tocopy
-                          * sizeof(struct __user_cap_data_struct))) {
+                          * sizeof(struct __user_cap_data_struct)))
                return -EFAULT;
-       }
 
        for (i = 0; i < tocopy; i++) {
                effective.cap[i] = kdata[i].effective;
@@ -473,32 +304,20 @@ asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
        if (ret)
                return ret;
 
-       if (pid && (pid != task_pid_vnr(current)))
-               ret = do_sys_capset_other_tasks(pid, &effective, &inheritable,
-                                               &permitted);
-       else {
-               /*
-                * This lock is required even when filesystem
-                * capability support is configured - it protects the
-                * sys_capget() call from returning incorrect data in
-                * the case that the targeted process is not the
-                * current one.
-                */
-               spin_lock(&task_capability_lock);
-
-               ret = security_capset_check(current, &effective, &inheritable,
-                                           &permitted);
-               /*
-                * Having verified that the proposed changes are
-                * legal, we now put them into effect.
-                */
-               if (!ret)
-                       security_capset_set(current, &effective, &inheritable,
-                                           &permitted);
-               spin_unlock(&task_capability_lock);
-       }
-
+       /* This lock is required even when filesystem capability support is
+        * configured - it protects the sys_capget() call from returning
+        * incorrect data in the case that the targeted process is not the
+        * current one.
+        */
+       spin_lock(&task_capability_lock);
 
+       ret = security_capset_check(&effective, &inheritable, &permitted);
+       /* Having verified that the proposed changes are legal, we now put them
+        * into effect.
+        */
+       if (!ret)
+               security_capset_set(&effective, &inheritable, &permitted);
+       spin_unlock(&task_capability_lock);
        return ret;
 }