selinux: distinguish non-init user namespace capability checks
Distinguish capability checks against a target associated
with the init user namespace versus capability checks against
a target associated with a non-init user namespace by defining
and using separate security classes for the latter.
This is needed to support e.g. Chrome usage of user namespaces
for the Chrome sandbox without needing to allow Chrome to also
exercise capabilities on targets in the init user namespace.
Suggested-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 474011c..bbff80c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1631,7 +1631,7 @@
/* Check whether a task is allowed to use a capability. */
static int cred_has_capability(const struct cred *cred,
- int cap, int audit)
+ int cap, int audit, bool initns)
{
struct common_audit_data ad;
struct av_decision avd;
@@ -1645,10 +1645,10 @@
switch (CAP_TO_INDEX(cap)) {
case 0:
- sclass = SECCLASS_CAPABILITY;
+ sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
break;
case 1:
- sclass = SECCLASS_CAPABILITY2;
+ sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
break;
default:
printk(KERN_ERR
@@ -2152,7 +2152,7 @@
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
int cap, int audit)
{
- return cred_has_capability(cred, cap, audit);
+ return cred_has_capability(cred, cap, audit, ns == &init_user_ns);
}
static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
@@ -2230,7 +2230,7 @@
int rc, cap_sys_admin = 0;
rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
- SECURITY_CAP_NOAUDIT);
+ SECURITY_CAP_NOAUDIT, true);
if (rc == 0)
cap_sys_admin = 1;
@@ -3213,7 +3213,7 @@
SECURITY_CAP_NOAUDIT);
if (!error)
error = cred_has_capability(current_cred(), CAP_MAC_ADMIN,
- SECURITY_CAP_NOAUDIT);
+ SECURITY_CAP_NOAUDIT, true);
isec = inode_security(inode);
if (!error)
error = security_sid_to_context_force(isec->sid, &context,
@@ -3390,7 +3390,7 @@
case KDSKBENT:
case KDSKBSENT:
error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
- SECURITY_CAP_AUDIT);
+ SECURITY_CAP_AUDIT, true);
break;
/* default case assumes that the command will go