Merge master.kernel.org:/home/rmk/linux-2.6-arm

[sfrench/cifs-2.6.git] / security / commoncap.c

diff --git a/security/commoncap.c b/security/commoncap.c
index 01ab47845dcf55e9fda443a2b9c952e2b356c9f8..06d5c9469ba3bf260342c2cf80a3e256c6b16f18 100644 (file)
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -25,20 +25,6 @@
 #include <linux/mount.h>
 #include <linux/sched.h>
 
-#ifdef CONFIG_SECURITY_FILE_CAPABILITIES
-/*
- * Because of the reduced scope of CAP_SETPCAP when filesystem
- * capabilities are in effect, it is safe to allow this capability to
- * be available in the default configuration.
- */
-# define CAP_INIT_BSET  CAP_FULL_SET
-#else /* ie. ndef CONFIG_SECURITY_FILE_CAPABILITIES */
-# define CAP_INIT_BSET  CAP_INIT_EFF_SET
-#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */
-
-kernel_cap_t cap_bset = CAP_INIT_BSET;    /* systemwide capability bound */
-EXPORT_SYMBOL(cap_bset);
-
 /* Global security state */
 
 unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
@@ -140,6 +126,12 @@ int cap_capset_check (struct task_struct *target, kernel_cap_t *effective,
                /* incapable of using this inheritable set */
                return -EPERM;
        }
+       if (!cap_issubset(*inheritable,
+                          cap_combine(target->cap_inheritable,
+                                      current->cap_bset))) {
+               /* no new pI capabilities outside bounding set */
+               return -EPERM;
+       }
 
        /* verify restrictions on target's new Permitted set */
        if (!cap_issubset (*permitted,
@@ -337,10 +329,11 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe)
        /* Derived from fs/exec.c:compute_creds. */
        kernel_cap_t new_permitted, working;
 
-       new_permitted = cap_intersect (bprm->cap_permitted, cap_bset);
-       working = cap_intersect (bprm->cap_inheritable,
+       new_permitted = cap_intersect(bprm->cap_permitted,
+                                current->cap_bset);
+       working = cap_intersect(bprm->cap_inheritable,
                                 current->cap_inheritable);
-       new_permitted = cap_combine (new_permitted, working);
+       new_permitted = cap_combine(new_permitted, working);
 
        if (bprm->e_uid != current->uid || bprm->e_gid != current->gid ||
            !cap_issubset (new_permitted, current->cap_permitted)) {
@@ -547,39 +540,21 @@ int cap_task_setnice (struct task_struct *p, int nice)
        return cap_safe_nice(p);
 }
 
-int cap_task_kill(struct task_struct *p, struct siginfo *info,
-                               int sig, u32 secid)
+/*
+ * called from kernel/sys.c for prctl(PR_CABSET_DROP)
+ * done without task_capability_lock() because it introduces
+ * no new races - i.e. only another task doing capget() on
+ * this task could get inconsistent info.  There can be no
+ * racing writer bc a task can only change its own caps.
+ */
+long cap_prctl_drop(unsigned long cap)
 {
-       if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
-               return 0;
-
-       /*
-        * Running a setuid root program raises your capabilities.
-        * Killing your own setuid root processes was previously
-        * allowed.
-        * We must preserve legacy signal behavior in this case.
-        */
-       if (p->euid == 0 && p->uid == current->uid)
-               return 0;
-
-       /* sigcont is permitted within same session */
-       if (sig == SIGCONT && (task_session_nr(current) == task_session_nr(p)))
-               return 0;
-
-       if (secid)
-               /*
-                * Signal sent as a particular user.
-                * Capabilities are ignored.  May be wrong, but it's the
-                * only thing we can do at the moment.
-                * Used only by usb drivers?
-                */
-               return 0;
-       if (cap_issubset(p->cap_permitted, current->cap_permitted))
-               return 0;
-       if (capable(CAP_KILL))
-               return 0;
-
-       return -EPERM;
+       if (!capable(CAP_SETPCAP))
+               return -EPERM;
+       if (!cap_valid(cap))
+               return -EINVAL;
+       cap_lower(current->cap_bset, cap);
+       return 0;
 }
 #else
 int cap_task_setscheduler (struct task_struct *p, int policy,
@@ -595,11 +570,6 @@ int cap_task_setnice (struct task_struct *p, int nice)
 {
        return 0;
 }
-int cap_task_kill(struct task_struct *p, struct siginfo *info,
-                               int sig, u32 secid)
-{
-       return 0;
-}
 #endif
 
 void cap_task_reparent_to_init (struct task_struct *p)