Merge tag 'apparmor-pr-2021-11-10' of...

Merge tag 'apparmor-pr-2021-11-10' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features
   - use per file locks for transactional queries
   - update policy management capability checks to work with LSM stacking

  Bug Fixes:
   - check/put label on apparmor_sk_clone_security()
   - fix error check on update of label hname
   - fix introspection of of task mode for unconfined tasks

  Cleanups:
   - avoid -Wempty-body warning
   - remove duplicated 'Returns:' comments
   - fix doc warning
   - remove unneeded one-line hook wrappers
   - use struct_size() helper in kzalloc()
   - fix zero-length compiler warning in AA_BUG()
   - file.h: delete duplicated word
   - delete repeated words in comments
   - remove repeated declaration"

* tag 'apparmor-pr-2021-11-10' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: remove duplicated 'Returns:' comments
  apparmor: remove unneeded one-line hook wrappers
  apparmor: Use struct_size() helper in kzalloc()
  apparmor: fix zero-length compiler warning in AA_BUG()
  apparmor: use per file locks for transactional queries
  apparmor: fix doc warning
  apparmor: Remove the repeated declaration
  apparmor: avoid -Wempty-body warning
  apparmor: Fix internal policy capable check for policy management
  apparmor: fix error check
  security: apparmor: delete repeated words in comments
  security: apparmor: file.h: delete duplicated word
  apparmor: switch to apparmor to internal capable check for policy management
  apparmor: update policy capable checks to use a label
  apparmor: fix introspection of of task mode for unconfined tasks
  apparmor: check/put label on apparmor_sk_clone_security()

security/apparmor/apparmorfs.c

@@ -812,8 +812,6 @@ struct multi_transaction {
 };
 
 #define MULTI_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct multi_transaction))
-/* TODO: replace with per file lock */
-static DEFINE_SPINLOCK(multi_transaction_lock);
 
 static void multi_transaction_kref(struct kref *kref)
 {
@@ -847,10 +845,10 @@ static void multi_transaction_set(struct file *file,
 	AA_BUG(n > MULTI_TRANSACTION_LIMIT);
 
 	new->size = n;
-	spin_lock(&multi_transaction_lock);
+	spin_lock(&file->f_lock);
 	old = (struct multi_transaction *) file->private_data;
 	file->private_data = new;
-	spin_unlock(&multi_transaction_lock);
+	spin_unlock(&file->f_lock);
 	put_multi_transaction(old);
 }
 
@@ -879,9 +877,10 @@ static ssize_t multi_transaction_read(struct file *file, char __user *buf,
 	struct multi_transaction *t;
 	ssize_t ret;
 
-	spin_lock(&multi_transaction_lock);
+	spin_lock(&file->f_lock);
 	t = get_multi_transaction(file->private_data);
-	spin_unlock(&multi_transaction_lock);
+	spin_unlock(&file->f_lock);
+
 	if (!t)
 		return 0;
 
@@ -1358,7 +1357,7 @@ static int rawdata_open(struct inode *inode, struct file *file)
 	struct aa_loaddata *loaddata;
 	struct rawdata_f_data *private;
 
-	if (!policy_view_capable(NULL))
+	if (!aa_current_policy_view_capable(NULL))
 		return -EACCES;
 
 	loaddata = __aa_get_loaddata(inode->i_private);
@@ -2114,7 +2113,7 @@ static struct aa_profile *__first_profile(struct aa_ns *root,
 
 /**
  * __next_profile - step to the next profile in a profile tree
- * @profile: current profile in tree (NOT NULL)
+ * @p: current profile in tree (NOT NULL)
  *
  * Perform a depth first traversal on the profile tree in a namespace
  *
@@ -2265,7 +2264,7 @@ static const struct seq_operations aa_sfs_profiles_op = {
 
 static int profiles_open(struct inode *inode, struct file *file)
 {
-	if (!policy_view_capable(NULL))
+	if (!aa_current_policy_view_capable(NULL))
 		return -EACCES;
 
 	return seq_open(file, &aa_sfs_profiles_op);

security/apparmor/include/file.h

@@ -167,7 +167,7 @@ int aa_audit_file(struct aa_profile *profile, struct aa_perms *perms,
  * @perms: permission table indexed by the matched state accept entry of @dfa
  * @trans: transition table for indexed by named x transitions
  *
- * File permission are determined by matching a path against @dfa and then
+ * File permission are determined by matching a path against @dfa and
  * then using the value of the accept entry for the matching state as
  * an index into @perms.  If a named exec transition is required it is
  * looked up in the transition table.

security/apparmor/include/label.h

@@ -77,10 +77,6 @@ struct aa_labelset {
 #define __labelset_for_each(LS, N) \
 	for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N))
 
-void aa_labelset_destroy(struct aa_labelset *ls);
-void aa_labelset_init(struct aa_labelset *ls);
-
-
 enum label_flags {
 	FLAG_HAT = 1,			/* profile is a hat */
 	FLAG_UNCONFINED = 2,		/* label unconfined only if all */
@@ -148,6 +144,7 @@ do {							\
 #define __label_make_stale(X) ((X)->flags |= FLAG_STALE)
 #define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size))
 #define labels_set(X) (&labels_ns(X)->labels)
+#define labels_view(X) labels_ns(X)
 #define labels_profile(X) ((X)->vec[(X)->size - 1])
 
 

security/apparmor/include/lib.h

@@ -31,12 +31,17 @@
 
 #define AA_WARN(X) WARN((X), "APPARMOR WARN %s: %s\n", __func__, #X)
 
-#define AA_BUG(X, args...) AA_BUG_FMT((X), "" args)
+#define AA_BUG(X, args...)						    \
+	do {								    \
+		_Pragma("GCC diagnostic ignored \"-Wformat-zero-length\""); \
+		AA_BUG_FMT((X), "" args);				    \
+		_Pragma("GCC diagnostic warning \"-Wformat-zero-length\""); \
+	} while (0)
 #ifdef CONFIG_SECURITY_APPARMOR_DEBUG_ASSERTS
 #define AA_BUG_FMT(X, fmt, args...)					\
 	WARN((X), "AppArmor WARN %s: (" #X "): " fmt, __func__, ##args)
 #else
-#define AA_BUG_FMT(X, fmt, args...)
+#define AA_BUG_FMT(X, fmt, args...) no_printk(fmt, ##args)
 #endif
 
 #define AA_ERROR(fmt, args...)						\

security/apparmor/include/policy.h

@@ -301,9 +301,11 @@ static inline int AUDIT_MODE(struct aa_profile *profile)
 	return profile->audit;
 }
 
-bool policy_view_capable(struct aa_ns *ns);
-bool policy_admin_capable(struct aa_ns *ns);
+bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns);
+bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns);
 int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns,
 			 u32 mask);
+bool aa_current_policy_view_capable(struct aa_ns *ns);
+bool aa_current_policy_admin_capable(struct aa_ns *ns);
 
 #endif /* __AA_POLICY_H */

security/apparmor/label.c

@@ -425,8 +425,7 @@ struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp)
 	AA_BUG(size < 1);
 
 	/*  + 1 for null terminator entry on vec */
-	new = kzalloc(sizeof(*new) + sizeof(struct aa_profile *) * (size + 1),
-			gfp);
+	new = kzalloc(struct_size(new, vec, size + 1), gfp);
 	AA_DEBUG("%s (%p)\n", __func__, new);
 	if (!new)
 		goto fail;
@@ -1454,7 +1453,7 @@ bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp)
 	if (label->hname || labels_ns(label) != ns)
 		return res;
 
-	if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) == -1)
+	if (aa_label_acntsxprint(&name, ns, label, FLAGS_NONE, gfp) < 0)
 		return res;
 
 	ls = labels_set(label);
@@ -1704,7 +1703,7 @@ int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
 
 /**
  * aa_label_acntsxprint - allocate a __counted string buffer and print label
- * @strp: buffer to write to. (MAY BE NULL if @size == 0)
+ * @strp: buffer to write to.
  * @ns: namespace profile is being viewed from
  * @label: label to view (NOT NULL)
  * @flags: flags controlling what label info is printed

security/apparmor/lsm.c

@@ -1402,7 +1402,7 @@ static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_admin_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
 		return -EPERM;
 	return param_set_bool(val, kp);
 }
@@ -1411,7 +1411,7 @@ static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_view_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_bool(buffer, kp);
 }
@@ -1420,7 +1420,7 @@ static int param_set_aabool(const char *val, const struct kernel_param *kp)
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_admin_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
 		return -EPERM;
 	return param_set_bool(val, kp);
 }
@@ -1429,7 +1429,7 @@ static int param_get_aabool(char *buffer, const struct kernel_param *kp)
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_view_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_bool(buffer, kp);
 }
@@ -1455,7 +1455,7 @@ static int param_get_aauint(char *buffer, const struct kernel_param *kp)
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_view_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_uint(buffer, kp);
 }
@@ -1526,7 +1526,7 @@ static int param_get_aacompressionlevel(char *buffer,
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_view_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
 		return -EPERM;
 	return param_get_int(buffer, kp);
 }
@@ -1535,7 +1535,7 @@ static int param_get_audit(char *buffer, const struct kernel_param *kp)
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_view_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
 		return -EPERM;
 	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
 }
@@ -1548,7 +1548,7 @@ static int param_set_audit(const char *val, const struct kernel_param *kp)
 		return -EINVAL;
 	if (!val)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_admin_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
 		return -EPERM;
 
 	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
@@ -1563,7 +1563,7 @@ static int param_get_mode(char *buffer, const struct kernel_param *kp)
 {
 	if (!apparmor_enabled)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_view_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
 		return -EPERM;
 
 	return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
@@ -1577,7 +1577,7 @@ static int param_set_mode(const char *val, const struct kernel_param *kp)
 		return -EINVAL;
 	if (!val)
 		return -EINVAL;
-	if (apparmor_initialized && !policy_admin_capable(NULL))
+	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
 		return -EPERM;
 
 	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
@@ -1713,7 +1713,7 @@ static int __init alloc_buffers(void)
 static int apparmor_dointvec(struct ctl_table *table, int write,
 			     void *buffer, size_t *lenp, loff_t *ppos)
 {
-	if (!policy_admin_capable(NULL))
+	if (!aa_current_policy_admin_capable(NULL))
 		return -EPERM;
 	if (!apparmor_enabled)
 		return -EINVAL;
@@ -1773,32 +1773,16 @@ static unsigned int apparmor_ip_postroute(void *priv,
 
 }
 
-static unsigned int apparmor_ipv4_postroute(void *priv,
-					    struct sk_buff *skb,
-					    const struct nf_hook_state *state)
-{
-	return apparmor_ip_postroute(priv, skb, state);
-}
-
-#if IS_ENABLED(CONFIG_IPV6)
-static unsigned int apparmor_ipv6_postroute(void *priv,
-					    struct sk_buff *skb,
-					    const struct nf_hook_state *state)
-{
-	return apparmor_ip_postroute(priv, skb, state);
-}
-#endif
-
 static const struct nf_hook_ops apparmor_nf_ops[] = {
 	{
-		.hook =         apparmor_ipv4_postroute,
+		.hook =         apparmor_ip_postroute,
 		.pf =           NFPROTO_IPV4,
 		.hooknum =      NF_INET_POST_ROUTING,
 		.priority =     NF_IP_PRI_SELINUX_FIRST,
 	},
 #if IS_ENABLED(CONFIG_IPV6)
 	{
-		.hook =         apparmor_ipv6_postroute,
+		.hook =         apparmor_ip_postroute,
 		.pf =           NFPROTO_IPV6,
 		.hooknum =      NF_INET_POST_ROUTING,
 		.priority =     NF_IP6_PRI_SELINUX_FIRST,

security/apparmor/path.c

@@ -83,7 +83,7 @@ static int disconnect(const struct path *path, char *buf, char **name,
  *
  * Returns: %0 else error code if path lookup fails
  *          When no error the path name is returned in @name which points to
- *          to a position in @buf
+ *          a position in @buf
  */
 static int d_namespace_path(const struct path *path, char *buf, char **name,
 			    int flags, const char *disconnected)

security/apparmor/policy.c

@@ -260,8 +260,7 @@ struct aa_profile *aa_alloc_profile(const char *hname, struct aa_proxy *proxy,
 	struct aa_profile *profile;
 
 	/* freed by free_profile - usually through aa_put_profile */
-	profile = kzalloc(sizeof(*profile) + sizeof(struct aa_profile *) * 2,
-			  gfp);
+	profile = kzalloc(struct_size(profile, label.vec, 2), gfp);
 	if (!profile)
 		return NULL;
 
@@ -632,18 +631,35 @@ static int audit_policy(struct aa_label *label, const char *op,
 	return error;
 }
 
+/* don't call out to other LSMs in the stack for apparmor policy admin
+ * permissions
+ */
+static int policy_ns_capable(struct aa_label *label,
+			     struct user_namespace *userns, int cap)
+{
+	int err;
+
+	/* check for MAC_ADMIN cap in cred */
+	err = cap_capable(current_cred(), userns, cap, CAP_OPT_NONE);
+	if (!err)
+		err = aa_capable(label, cap, CAP_OPT_NONE);
+
+	return err;
+}
+
 /**
- * policy_view_capable - check if viewing policy in at @ns is allowed
- * ns: namespace being viewed by current task (may be NULL)
+ * aa_policy_view_capable - check if viewing policy in at @ns is allowed
+ * label: label that is trying to view policy in ns
+ * ns: namespace being viewed by @label (may be NULL if @label's ns)
  * Returns: true if viewing policy is allowed
  *
  * If @ns is NULL then the namespace being viewed is assumed to be the
  * tasks current namespace.
  */
-bool policy_view_capable(struct aa_ns *ns)
+bool aa_policy_view_capable(struct aa_label *label, struct aa_ns *ns)
 {
 	struct user_namespace *user_ns = current_user_ns();
-	struct aa_ns *view_ns = aa_get_current_ns();
+	struct aa_ns *view_ns = labels_view(label);
 	bool root_in_user_ns = uid_eq(current_euid(), make_kuid(user_ns, 0)) ||
 			       in_egroup_p(make_kgid(user_ns, 0));
 	bool response = false;
@@ -655,20 +671,44 @@ bool policy_view_capable(struct aa_ns *ns)
 	     (unprivileged_userns_apparmor_policy != 0 &&
 	      user_ns->level == view_ns->level)))
 		response = true;
-	aa_put_ns(view_ns);
 
 	return response;
 }
 
-bool policy_admin_capable(struct aa_ns *ns)
+bool aa_policy_admin_capable(struct aa_label *label, struct aa_ns *ns)
 {
 	struct user_namespace *user_ns = current_user_ns();
-	bool capable = ns_capable(user_ns, CAP_MAC_ADMIN);
+	bool capable = policy_ns_capable(label, user_ns, CAP_MAC_ADMIN) == 0;
 
 	AA_DEBUG("cap_mac_admin? %d\n", capable);
 	AA_DEBUG("policy locked? %d\n", aa_g_lock_policy);
 
-	return policy_view_capable(ns) && capable && !aa_g_lock_policy;
+	return aa_policy_view_capable(label, ns) && capable &&
+		!aa_g_lock_policy;
+}
+
+bool aa_current_policy_view_capable(struct aa_ns *ns)
+{
+	struct aa_label *label;
+	bool res;
+
+	label = __begin_current_label_crit_section();
+	res = aa_policy_view_capable(label, ns);
+	__end_current_label_crit_section(label);
+
+	return res;
+}
+
+bool aa_current_policy_admin_capable(struct aa_ns *ns)
+{
+	struct aa_label *label;
+	bool res;
+
+	label = __begin_current_label_crit_section();
+	res = aa_policy_admin_capable(label, ns);
+	__end_current_label_crit_section(label);
+
+	return res;
 }
 
 /**
@@ -694,7 +734,7 @@ int aa_may_manage_policy(struct aa_label *label, struct aa_ns *ns, u32 mask)
 		return audit_policy(label, op, NULL, NULL, "policy_locked",
 				    -EACCES);
 
-	if (!policy_admin_capable(ns))
+	if (!aa_policy_admin_capable(label, ns))
 		return audit_policy(label, op, NULL, NULL, "not policy admin",
 				    -EACCES);
 

security/apparmor/policy_unpack.c

@@ -39,7 +39,7 @@
 
 /*
  * The AppArmor interface treats data as a type byte followed by the
- * actual data.  The interface has the notion of a a named entry
+ * actual data.  The interface has the notion of a named entry
  * which has a name (AA_NAME typecode followed by name string) followed by
  * the entries typecode and data.  Named types allow for optional
  * elements and extensions to be added and tested for without breaking

security/apparmor/procattr.c

@@ -21,8 +21,6 @@
  * @profile: the profile to print profile info about  (NOT NULL)
  * @string: Returns - string containing the profile info (NOT NULL)
  *
- * Returns: length of @string on success else error on failure
- *
  * Requires: profile != NULL
  *
  * Creates a string containing the namespace_name://profile_name for