Add a new capable interface that will be used by systems that use audit to
make an A or B type decision instead of a security decision. Currently
this is the case at least for filesystems when deciding if a process can use
the reserved 'root' blocks and for the case of things like the oom
algorithm determining if processes are root processes and should be less
likely to be killed. These types of security system requests should not be
audited or logged since they are not really security decisions. It would be
possible to solve this problem like the vm_enough_memory security check did
by creating a new LSM interface and moving all of the policy into that
interface but proves the needlessly bloat the LSM and provide complex
indirection.
This merely allows those decisions to be made where they belong and to not
flood logs or printk with denials for thing that are not security decisions.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/commoncap.c b/security/commoncap.c
index d453933..dc06c00 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -49,7 +49,7 @@
* returns 0 when a task has a capability, but the kernel's capable()
* returns 1 for this case.
*/
-int cap_capable (struct task_struct *tsk, int cap)
+int cap_capable(struct task_struct *tsk, int cap, int audit)
{
/* Derived from include/linux/sched.h:capable. */
if (cap_raised(tsk->cap_effective, cap))
@@ -112,7 +112,7 @@
* to the old permitted set. That is, if the current task
* does *not* possess the CAP_SETPCAP capability.
*/
- return (cap_capable(current, CAP_SETPCAP) != 0);
+ return (cap_capable(current, CAP_SETPCAP, SECURITY_CAP_AUDIT) != 0);
}
static inline int cap_limit_ptraced_target(void) { return 1; }
@@ -677,7 +677,7 @@
|| ((current->securebits & SECURE_ALL_LOCKS
& ~arg2)) /*[2]*/
|| (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/
- || (cap_capable(current, CAP_SETPCAP) != 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
@@ -742,7 +742,7 @@
{
int cap_sys_admin = 0;
- if (cap_capable(current, CAP_SYS_ADMIN) == 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);
}