Merge tag 'selinux-pr-20220801' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "A relatively small set of patches for SELinux this time, eight patches
  in total with really only one significant change.

  The highlights are:

   - Add support for proper labeling of memfd_secret anonymous inodes.

     This will allow LSMs that implement the anonymous inode hooks to
     apply security policy to memfd_secret() fds.

   - Various small improvements to memory management: fixed leaks, freed
     memory when needed, boundary checks.

   - Hardened the selinux_audit_data struct with __randomize_layout.

   - A minor documentation tweak to fix a formatting/style issue"

* tag 'selinux-pr-20220801' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: selinux_add_opt() callers free memory
  selinux: Add boundary check in put_entry()
  selinux: fix memleak in security_read_state_kernel()
  docs: selinux: add '=' signs to kernel boot options
  mm: create security context for memfd_secret inodes
  selinux: fix typos in comments
  selinux: drop unnecessary NULL check
  selinux: add __randomize_layout to selinux_audit_data

5 files changed, 19 insertions, 13 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 1bbd53321d13..79573504783b 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -640,7 +640,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 	 * we need to skip the double mount verification.
 	 *
 	 * This does open a hole in which we will not notice if the first
-	 * mount using this sb set explict options and a second mount using
+	 * mount using this sb set explicit options and a second mount using
 	 * this sb does not set any security options.  (The first options
 	 * will be used for both mounts)
 	 */
@@ -944,10 +944,12 @@ out:
 	return rc;
 }
 
+/*
+ * NOTE: the caller is resposible for freeing the memory even if on error.
+ */
 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 {
 	struct selinux_mnt_opts *opts = *mnt_opts;
-	bool is_alloc_opts = false;
 	u32 *dst_sid;
 	int rc;
 
@@ -955,7 +957,7 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 		/* eaten and completely ignored */
 		return 0;
 	if (!s)
-		return -ENOMEM;
+		return -EINVAL;
 
 	if (!selinux_initialized(&selinux_state)) {
 		pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
@@ -967,7 +969,6 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 		if (!opts)
 			return -ENOMEM;
 		*mnt_opts = opts;
-		is_alloc_opts = true;
 	}
 
 	switch (token) {
@@ -1002,10 +1003,6 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts)
 	return rc;
 
 err:
-	if (is_alloc_opts) {
-		kfree(opts);
-		*mnt_opts = NULL;
-	}
 	pr_warn(SEL_MOUNT_FAIL_MSG);
 	return -EINVAL;
 }
@@ -1019,7 +1016,7 @@ static int show_sid(struct seq_file *m, u32 sid)
 	rc = security_sid_to_context(&selinux_state, sid,
 					     &context, &len);
 	if (!rc) {
-		bool has_comma = context && strchr(context, ',');
+		bool has_comma = strchr(context, ',');
 
 		seq_putc(m, '=');
 		if (has_comma)
@@ -6792,7 +6789,7 @@ static u32 bpf_map_fmode_to_av(fmode_t fmode)
 }
 
 /* This function will check the file pass through unix socket or binder to see
- * if it is a bpf related object. And apply correspinding checks on the bpf
+ * if it is a bpf related object. And apply corresponding checks on the bpf
  * object based on the type. The bpf maps and programs, not like other files and
  * socket, are using a shared anonymous inode inside the kernel as their inode.
  * So checking that inode cannot identify if the process have privilege to
diff --git a/security/selinux/include/audit.h b/security/selinux/include/audit.h
index 1cba83d17f41..406bceb90c6c 100644
--- a/security/selinux/include/audit.h
+++ b/security/selinux/include/audit.h
@@ -18,7 +18,7 @@
 /**
  *	selinux_audit_rule_init - alloc/init an selinux audit rule structure.
  *	@field: the field this rule refers to
- *	@op: the operater the rule uses
+ *	@op: the operator the rule uses
  *	@rulestr: the text "target" of the rule
  *	@rule: pointer to the new rule structure returned via this
  *
diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
index 2b372f98f2d7..5525b94fd266 100644
--- a/security/selinux/include/avc.h
+++ b/security/selinux/include/avc.h
@@ -53,7 +53,7 @@ struct selinux_audit_data {
 	u32 denied;
 	int result;
 	struct selinux_state *state;
-};
+} __randomize_layout;
 
 /*
  * AVC operations
diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h
index c24d4e1063ea..ffc4e7bad205 100644
--- a/security/selinux/ss/policydb.h
+++ b/security/selinux/ss/policydb.h
@@ -370,6 +370,8 @@ static inline int put_entry(const void *buf, size_t bytes, int num, struct polic
 {
 	size_t len = bytes * num;
 
+	if (len > fp->len)
+		return -EINVAL;
 	memcpy(fp->data, buf, len);
 	fp->data += len;
 	fp->len -= len;
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 69b2734311a6..fe5fcf571c56 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -4048,6 +4048,7 @@ int security_read_policy(struct selinux_state *state,
 int security_read_state_kernel(struct selinux_state *state,
 			       void **data, size_t *len)
 {
+	int err;
 	struct selinux_policy *policy;
 
 	policy = rcu_dereference_protected(
@@ -4060,5 +4061,11 @@ int security_read_state_kernel(struct selinux_state *state,
 	if (!*data)
 		return -ENOMEM;
 
-	return __security_read_policy(policy, *data, len);
+	err = __security_read_policy(policy, *data, len);
+	if (err) {
+		vfree(*data);
+		*data = NULL;
+		*len = 0;
+	}
+	return err;
 }