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-rw-r--r--fs/namespace.c4
-rw-r--r--include/linux/security.h13
-rw-r--r--security/capability.c6
-rw-r--r--security/security.c5
4 files changed, 28 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 3ddfd9046c4..1b3f2ac59c5 100644
--- a/fs/namespace.c
+++ b/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);
diff --git a/include/linux/security.h b/include/linux/security.h
index 14167f2eb35..d11ac43ecc4 100644
--- a/include/linux/security.h
+++ b/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;
diff --git a/security/capability.c b/security/capability.c
index 85b67c8632d..ab3d807accc 100644
--- a/security/capability.c
+++ b/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);
diff --git a/security/security.c b/security/security.c
index 8f28685ee0d..b1d6134548b 100644
--- a/security/security.c
+++ b/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);