[PATCH 3/3] AppArmor: add support for lsm_manage_policy
From: Maxime Bélair <hidden>
Date: 2025-05-06 14:40:03
Also in:
linux-api, lkml
Subsystem:
apparmor security module, security subsystem, the rest · Maintainers:
John Johansen, John Johansen, Georgia Garcia, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
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 <redacted> --- 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