Commit 58acf9d9 authored by John Johansen's avatar John Johansen

apparmor: fix module parameters can be changed after policy is locked

the policy_lock parameter is a one way switch that prevents policy
from being further modified. Unfortunately some of the module parameters
can effectively modify policy by turning off enforcement.

split policy_admin_capable into a view check and a full admin check,
and update the admin check to test the policy_lock parameter.
Signed-off-by: default avatarJohn Johansen <john.johansen@canonical.com>
parent 5f20fdfe
......@@ -403,6 +403,8 @@ static inline int AUDIT_MODE(struct aa_profile *profile)
return profile->audit;
}
bool policy_view_capable(void);
bool policy_admin_capable(void);
bool aa_may_manage_policy(int op);
#endif /* __AA_POLICY_H */
......@@ -730,51 +730,49 @@ __setup("apparmor=", apparmor_enabled_setup);
/* set global flag turning off the ability to load policy */
static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_admin_capable())
return -EPERM;
if (aa_g_lock_policy)
return -EACCES;
return param_set_bool(val, kp);
}
static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_view_capable())
return -EPERM;
return param_get_bool(buffer, kp);
}
static int param_set_aabool(const char *val, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_admin_capable())
return -EPERM;
return param_set_bool(val, kp);
}
static int param_get_aabool(char *buffer, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_view_capable())
return -EPERM;
return param_get_bool(buffer, kp);
}
static int param_set_aauint(const char *val, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_admin_capable())
return -EPERM;
return param_set_uint(val, kp);
}
static int param_get_aauint(char *buffer, const struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_view_capable())
return -EPERM;
return param_get_uint(buffer, kp);
}
static int param_get_audit(char *buffer, struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_view_capable())
return -EPERM;
if (!apparmor_enabled)
......@@ -786,7 +784,7 @@ static int param_get_audit(char *buffer, struct kernel_param *kp)
static int param_set_audit(const char *val, struct kernel_param *kp)
{
int i;
if (!capable(CAP_MAC_ADMIN))
if (!policy_admin_capable())
return -EPERM;
if (!apparmor_enabled)
......@@ -807,7 +805,7 @@ static int param_set_audit(const char *val, struct kernel_param *kp)
static int param_get_mode(char *buffer, struct kernel_param *kp)
{
if (!capable(CAP_MAC_ADMIN))
if (!policy_admin_capable())
return -EPERM;
if (!apparmor_enabled)
......@@ -819,7 +817,7 @@ static int param_get_mode(char *buffer, struct kernel_param *kp)
static int param_set_mode(const char *val, struct kernel_param *kp)
{
int i;
if (!capable(CAP_MAC_ADMIN))
if (!policy_admin_capable())
return -EPERM;
if (!apparmor_enabled)
......
......@@ -918,6 +918,22 @@ static int audit_policy(int op, gfp_t gfp, const char *name, const char *info,
&sa, NULL);
}
bool policy_view_capable(void)
{
struct user_namespace *user_ns = current_user_ns();
bool response = false;
if (ns_capable(user_ns, CAP_MAC_ADMIN))
response = true;
return response;
}
bool policy_admin_capable(void)
{
return policy_view_capable() && !aa_g_lock_policy;
}
/**
* aa_may_manage_policy - can the current task manage policy
* @op: the policy manipulation operation being done
......@@ -932,7 +948,7 @@ bool aa_may_manage_policy(int op)
return 0;
}
if (!capable(CAP_MAC_ADMIN)) {
if (!policy_admin_capable()) {
audit_policy(op, GFP_KERNEL, NULL, "not policy admin", -EACCES);
return 0;
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment