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authorJohn Johansen <john.johansen@canonical.com>2012-04-12 16:47:51 -0500
committerJames Morris <james.l.morris@oracle.com>2012-04-14 11:13:18 +1000
commitc29bceb3967398cf2ac8bf8edf9634fdb722df7d (patch)
tree9feaa5a8b78812e48fa9b4e9b8b939f06390bee8 /security/apparmor
parent259e5e6c75a910f3b5e656151dc602f53f9d7548 (diff)
downloadlinux-c29bceb3967398cf2ac8bf8edf9634fdb722df7d.tar.gz
Fix execve behavior apparmor for PR_{GET,SET}_NO_NEW_PRIVS
Add support for AppArmor to explicitly fail requested domain transitions if NO_NEW_PRIVS is set and the task is not unconfined. Transitions from unconfined are still allowed because this always results in a reduction of privileges. Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Will Drewry <wad@chromium.org> Signed-off-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Andy Lutomirski <luto@amacapital.net> v18: new acked-by, new description Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'security/apparmor')
-rw-r--r--security/apparmor/domain.c39
1 files changed, 35 insertions, 4 deletions
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 18c88d06e88..b81ea10a17a 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -360,10 +360,6 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
if (bprm->cred_prepared)
return 0;
- /* XXX: no_new_privs is not usable with AppArmor yet */
- if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
- return -EPERM;
-
cxt = bprm->cred->security;
BUG_ON(!cxt);
@@ -398,6 +394,11 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
new_profile = find_attach(ns, &ns->base.profiles, name);
if (!new_profile)
goto cleanup;
+ /*
+ * NOTE: Domain transitions from unconfined are allowed
+ * even when no_new_privs is set because this aways results
+ * in a further reduction of permissions.
+ */
goto apply;
}
@@ -459,6 +460,16 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
/* fail exec */
error = -EACCES;
+ /*
+ * Policy has specified a domain transition, if no_new_privs then
+ * fail the exec.
+ */
+ if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) {
+ aa_put_profile(new_profile);
+ error = -EPERM;
+ goto cleanup;
+ }
+
if (!new_profile)
goto audit;
@@ -613,6 +624,14 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest)
const char *target = NULL, *info = NULL;
int error = 0;
+ /*
+ * Fail explicitly requested domain transitions if no_new_privs.
+ * There is no exception for unconfined as change_hat is not
+ * available.
+ */
+ if (current->no_new_privs)
+ return -EPERM;
+
/* released below */
cred = get_current_cred();
cxt = cred->security;
@@ -754,6 +773,18 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec,
cxt = cred->security;
profile = aa_cred_profile(cred);
+ /*
+ * Fail explicitly requested domain transitions if no_new_privs
+ * and not unconfined.
+ * Domain transitions from unconfined are allowed even when
+ * no_new_privs is set because this aways results in a reduction
+ * of permissions.
+ */
+ if (current->no_new_privs && !unconfined(profile)) {
+ put_cred(cred);
+ return -EPERM;
+ }
+
if (ns_name) {
/* released below */
ns = aa_find_namespace(profile->ns, ns_name);