---

yaml
---
r: 235111
b: refs/heads/master
c: ff36fe2
h: refs/heads/master
i:
  235109: cd8c257
  235107: f0e05c2
  235103: 9382e70
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2ad18bdf3b8f84c85c7da7e4de365f7c5701fb3f
+refs/heads/master: ff36fe2c845cab2102e4826c1ffa0a6ebf487c65

trunk/fs/namespace.c

@@ -1800,6 +1800,10 @@ static int do_remount(struct path *path, int flags, int mnt_flags,
 	if (path->dentry != path->mnt->mnt_root)
 		return -EINVAL;
 
+	err = security_sb_remount(sb, data);
+	if (err)
+		return err;
+
 	down_write(&sb->s_umount);
 	if (flags & MS_BIND)
 		err = change_mount_flags(path->mnt, flags);

trunk/include/linux/security.h

@@ -268,6 +268,12 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *	@orig the original mount data copied from userspace.
  *	@copy copied data which will be passed to the security module.
  *	Returns 0 if the copy was successful.
+ * @sb_remount:
+ *	Extracts security system specifc mount options and verifys no changes
+ *	are being made to those options.
+ *	@sb superblock being remounted
+ *	@data contains the filesystem-specific data.
+ *	Return 0 if permission is granted.
  * @sb_umount:
  *	Check permission before the @mnt file system is unmounted.
  *	@mnt contains the mounted file system.
@@ -1394,6 +1400,7 @@ struct security_operations {
 	int (*sb_alloc_security) (struct super_block *sb);
 	void (*sb_free_security) (struct super_block *sb);
 	int (*sb_copy_data) (char *orig, char *copy);
+	int (*sb_remount) (struct super_block *sb, void *data);
 	int (*sb_kern_mount) (struct super_block *sb, int flags, void *data);
 	int (*sb_show_options) (struct seq_file *m, struct super_block *sb);
 	int (*sb_statfs) (struct dentry *dentry);
@@ -1676,6 +1683,7 @@ int security_bprm_secureexec(struct linux_binprm *bprm);
 int security_sb_alloc(struct super_block *sb);
 void security_sb_free(struct super_block *sb);
 int security_sb_copy_data(char *orig, char *copy);
+int security_sb_remount(struct super_block *sb, void *data);
 int security_sb_kern_mount(struct super_block *sb, int flags, void *data);
 int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
@@ -1955,6 +1963,11 @@ static inline int security_sb_copy_data(char *orig, char *copy)
 	return 0;
 }
 
+static inline int security_sb_remount(struct super_block *sb, void *data)
+{
+	return 0;
+}
+
 static inline int security_sb_kern_mount(struct super_block *sb, int flags, void *data)
 {
 	return 0;

trunk/security/capability.c

@@ -54,6 +54,11 @@ static int cap_sb_copy_data(char *orig, char *copy)
 	return 0;
 }
 
+static int cap_sb_remount(struct super_block *sb, void *data)
+{
+	return 0;
+}
+
 static int cap_sb_kern_mount(struct super_block *sb, int flags, void *data)
 {
 	return 0;
@@ -887,6 +892,7 @@ void __init security_fixup_ops(struct security_operations *ops)
 	set_to_cap_if_null(ops, sb_alloc_security);
 	set_to_cap_if_null(ops, sb_free_security);
 	set_to_cap_if_null(ops, sb_copy_data);
+	set_to_cap_if_null(ops, sb_remount);
 	set_to_cap_if_null(ops, sb_kern_mount);
 	set_to_cap_if_null(ops, sb_show_options);
 	set_to_cap_if_null(ops, sb_statfs);

trunk/security/security.c

@@ -267,6 +267,11 @@ int security_sb_copy_data(char *orig, char *copy)
 }
 EXPORT_SYMBOL(security_sb_copy_data);
 
+int security_sb_remount(struct super_block *sb, void *data)
+{
+	return security_ops->sb_remount(sb, data);
+}
+
 int security_sb_kern_mount(struct super_block *sb, int flags, void *data)
 {
 	return security_ops->sb_kern_mount(sb, flags, data);