Revert "CRED: Fix regression in cap_capable() as shown up by sys_faccessat() [ver #2]"
This reverts commit 14eaddc967b16017d4a1a24d2be6c28ecbe06ed8.
David has a better version to come.
diff --git a/security/commoncap.c b/security/commoncap.c
index 7f0b2a6..7971354 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -43,44 +43,28 @@
EXPORT_SYMBOL(cap_netlink_recv);
/**
- * cap_capable - Determine whether current has a particular effective capability
+ * cap_capable - Determine whether a task has a particular effective capability
+ * @tsk: The task to query
* @cap: The capability to check for
* @audit: Whether to write an audit message or not
*
* Determine whether the nominated task has the specified capability amongst
- * its effective set, returning 0 if it does, -ve if it does not. Note that
- * this uses current's subjective/effective credentials.
+ * its effective set, returning 0 if it does, -ve if it does not.
*
* NOTE WELL: cap_capable() cannot be used like the kernel's capable()
* function. That is, it has the reverse semantics: cap_capable() returns 0
* when a task has a capability, but the kernel's capable() returns 1 for this
* case.
*/
-int cap_capable(int cap, int audit)
+int cap_capable(struct task_struct *tsk, int cap, int audit)
{
- return cap_raised(current_cap(), cap) ? 0 : -EPERM;
-}
+ __u32 cap_raised;
-/**
- * cap_has_capability - Determine whether a task has a particular effective capability
- * @tsk: The task to query
- * @cred: The credentials to use
- * @cap: The capability to check for
- * @audit: Whether to write an audit message or not
- *
- * Determine whether the nominated task has the specified capability amongst
- * its effective set, returning 0 if it does, -ve if it does not. Note that
- * this uses the task's objective/real credentials.
- *
- * NOTE WELL: cap_has_capability() cannot be used like the kernel's
- * has_capability() function. That is, it has the reverse semantics:
- * cap_has_capability() returns 0 when a task has a capability, but the
- * kernel's has_capability() returns 1 for this case.
- */
-int cap_task_capable(struct task_struct *tsk, const struct cred *cred, int cap,
- int audit)
-{
- return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM;
+ /* Derived from include/linux/sched.h:capable. */
+ rcu_read_lock();
+ cap_raised = cap_raised(__task_cred(tsk)->cap_effective, cap);
+ rcu_read_unlock();
+ return cap_raised ? 0 : -EPERM;
}
/**
@@ -176,7 +160,7 @@
/* they are so limited unless the current task has the CAP_SETPCAP
* capability
*/
- if (cap_capable(CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)
+ if (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0)
return 0;
#endif
return 1;
@@ -885,7 +869,7 @@
& (new->securebits ^ arg2)) /*[1]*/
|| ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/
|| (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
- || (cap_capable(CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/
+ || (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0) /*[4]*/
/*
* [1] no changing of bits that are locked
* [2] no unlocking of locks
@@ -966,7 +950,7 @@
{
int cap_sys_admin = 0;
- if (cap_capable(CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0)
+ if (cap_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT) == 0)
cap_sys_admin = 1;
return __vm_enough_memory(mm, pages, cap_sys_admin);
}