Enable users to manage AppArmor policies through the new hook
lsm_manage_policy. Currently, policies can be added but not replaced
using this new mechanism, ensuring that this interface can only further
confine the system.
Signed-off-by: Maxime Bélair <maxime.belair@xxxxxxxxxxxxx>
---
security/apparmor/apparmorfs.c | 19 +++++++++++++++++++
security/apparmor/include/apparmorfs.h | 3 +++
security/apparmor/lsm.c | 16 ++++++++++++++++
3 files changed, 38 insertions(+)
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 6039afae4bfc..9abb17e8fdd0 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -439,6 +439,25 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
return error;
}
+/**
+ * aa_profile_load_current_ns - load a profile into the current namespace
+ * @buf buffer containing the user-provided policy
+ * @size size of @buf
+ * @ppos position pointer in the file
+ *
+ * Returns: 0 on success, negative value on error
+ */
+ssize_t aa_profile_load_current_ns(const void __user *buf, size_t size,
+ loff_t *ppos)
+{
+ struct aa_ns *ns = aa_get_current_ns();
+ int error = policy_update(AA_MAY_LOAD_POLICY, buf, size, ppos, ns);
+
+ aa_put_ns(ns);
+
+ return error >= 0 ? 0 : error;
+}
+
/* .load file hook fn to load policy */
static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
loff_t *pos)
diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
index 1e94904f68d9..ba2384e3fb93 100644
--- a/security/apparmor/include/apparmorfs.h
+++ b/security/apparmor/include/apparmorfs.h
@@ -112,6 +112,9 @@ int __aafs_profile_mkdir(struct aa_profile *profile, struct dentry *parent);
void __aafs_ns_rmdir(struct aa_ns *ns);
int __aafs_ns_mkdir(struct aa_ns *ns, struct dentry *parent, const char *name,
struct dentry *dent);
+ssize_t aa_profile_load_current_ns(const void __user *buf, size_t size,
+ loff_t *ppos);
+
struct aa_loaddata;
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 9b6c2f157f83..21f3c4db0e4e 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1275,6 +1275,20 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
}
+static int apparmor_lsm_manage_policy(u32 lsm_id, u32 op, void __user *buf,
+ size_t size, u32 flags)
+{
+ loff_t pos = 0; // Partial writing is not currently supported
+
+ if (lsm_id != LSM_ID_APPARMOR)
+ return 0;
+
+ if (op != LSM_POLICY_LOAD || flags)
+ return -EOPNOTSUPP;
+
+ return aa_profile_load_current_ns(buf, size, &pos);
+}
+
#ifdef CONFIG_NETWORK_SECMARK
/**
* apparmor_socket_sock_rcv_skb - check perms before associating skb to sk
@@ -1483,6 +1497,8 @@ static struct security_hook_list apparmor_hooks[] __ro_after_init = {
LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
+
+ LSM_HOOK_INIT(lsm_manage_policy, apparmor_lsm_manage_policy),
#ifdef CONFIG_NETWORK_SECMARK
LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
#endif
--
2.48.1
