From: Andy Lutomirski <luto@amacapital.net>
To: Casey Schaufler <casey@schaufler-ca.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jamie Lokier <jamie@shareable.org>,
Will Drewry <wad@chromium.org>,
linux-kernel@vger.kernel.org, keescook@chromium.org,
john.johansen@canonical.com, serge.hallyn@canonical.com,
coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com,
djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org,
jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com,
penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu,
akpm@linux-foundation.org, khilman@ti.com,
borislav.petkov@amd.com, amwang@redhat.com, oleg@redhat.com,
ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de,
dhowells@redhat.com, daniel.lezcano@free.fr,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org, olofj@chromium.org,
mhalcrow@google.com, dlaor@redhat.com, corbet@lwn.net,
alan@lxorguk.ukuu.org.uk, Andy Lutomirski <luto@amacapital.net>
Subject: [PATCH v2 2/4] Fix apparmor for PR_{GET,SET}_NO_NEW_PRIVS
Date: Sun, 15 Jan 2012 16:37:19 -0800 [thread overview]
Message-ID: <3405cd6e7b219047a0c4171a0c56b90c29af9bb5.1326673414.git.luto@amacapital.net> (raw)
In-Reply-To: <cover.1326673414.git.luto@amacapital.net>
In-Reply-To: <cover.1326673414.git.luto@amacapital.net>
From: John Johansen <john.johansen@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
security/apparmor/domain.c | 39 +++++++++++++++++++++++++++++++++++----
1 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index a24ee44..7316d77 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 useable with AppArmor yet */
- if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
- return -EPERM;
-
cxt = bprm->cred->security;
BUG_ON(!cxt);
@@ -399,6 +395,11 @@ 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);
--
1.7.7.5
next prev parent reply other threads:[~2012-01-16 0:38 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 0:37 [PATCH v2 0/4] PR_SET_NO_NEW_PRIVS, unshare, and chroot Andy Lutomirski
2012-01-16 0:37 ` [PATCH v2 1/4] Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privs Andy Lutomirski
2012-01-16 17:33 ` Oleg Nesterov
2012-01-16 20:15 ` Andy Lutomirski
2012-01-16 0:37 ` Andy Lutomirski [this message]
2012-01-16 0:37 ` [PATCH v2 3/4] Allow unprivileged CLONE_NEWUTS and CLONE_NEWIPC with no_new_privs Andy Lutomirski
2012-01-16 0:37 ` [PATCH 4/4] Allow unprivileged chroot when safe Andy Lutomirski
2012-01-16 0:45 ` Linus Torvalds
2012-01-16 1:08 ` Andy Lutomirski
2012-01-16 19:26 ` Colin Walters
2012-01-16 20:18 ` Andy Lutomirski
2012-01-17 10:14 ` Jamie Lokier
2012-01-16 20:06 ` Al Viro
2012-01-16 20:15 ` Andy Lutomirski
2012-01-16 20:26 ` Al Viro
2012-01-17 16:23 ` Oleg Nesterov
2012-01-17 16:31 ` Andy Lutomirski
2012-01-16 1:04 ` [PATCH v2 0/4] PR_SET_NO_NEW_PRIVS, unshare, and chroot Andy Lutomirski
2012-01-16 20:49 ` Colin Walters
2012-01-16 21:25 ` Andy Lutomirski
2012-01-16 21:47 ` Colin Walters
2012-01-16 21:57 ` Andy Lutomirski
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