LSM: Add security_path_chroot().
This patch allows pathname based LSM modules to check chroot() operations.
This hook is used by TOMOYO.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/fs/open.c b/fs/open.c
index b5c294d..201041d 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -587,6 +587,9 @@
error = -EPERM;
if (!capable(CAP_SYS_CHROOT))
goto dput_and_out;
+ error = security_path_chroot(&path);
+ if (error)
+ goto dput_and_out;
set_fs_root(current->fs, &path);
error = 0;
diff --git a/include/linux/security.h b/include/linux/security.h
index c8a584c..ed0faea 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -459,6 +459,10 @@
* @uid contains new owner's ID.
* @gid contains new group's ID.
* Return 0 if permission is granted.
+ * @path_chroot:
+ * Check for permission to change root directory.
+ * @path contains the path structure.
+ * Return 0 if permission is granted.
* @inode_readlink:
* Check the permission to read the symbolic link.
* @dentry contains the dentry structure for the file link.
@@ -1503,6 +1507,7 @@
int (*path_chmod) (struct dentry *dentry, struct vfsmount *mnt,
mode_t mode);
int (*path_chown) (struct path *path, uid_t uid, gid_t gid);
+ int (*path_chroot) (struct path *path);
#endif
int (*inode_alloc_security) (struct inode *inode);
@@ -2970,6 +2975,7 @@
int security_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
mode_t mode);
int security_path_chown(struct path *path, uid_t uid, gid_t gid);
+int security_path_chroot(struct path *path);
#else /* CONFIG_SECURITY_PATH */
static inline int security_path_unlink(struct path *dir, struct dentry *dentry)
{
@@ -3031,6 +3037,11 @@
{
return 0;
}
+
+static inline int security_path_chroot(struct path *path)
+{
+ return 0;
+}
#endif /* CONFIG_SECURITY_PATH */
#ifdef CONFIG_KEYS
diff --git a/security/capability.c b/security/capability.c
index 09279a8..4f3ab47 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -319,6 +319,11 @@
{
return 0;
}
+
+static int cap_path_chroot(struct path *root)
+{
+ return 0;
+}
#endif
static int cap_file_permission(struct file *file, int mask)
@@ -990,6 +995,7 @@
set_to_cap_if_null(ops, path_truncate);
set_to_cap_if_null(ops, path_chmod);
set_to_cap_if_null(ops, path_chown);
+ set_to_cap_if_null(ops, path_chroot);
#endif
set_to_cap_if_null(ops, file_permission);
set_to_cap_if_null(ops, file_alloc_security);
diff --git a/security/security.c b/security/security.c
index 5259270..2797573 100644
--- a/security/security.c
+++ b/security/security.c
@@ -449,6 +449,11 @@
return 0;
return security_ops->path_chown(path, uid, gid);
}
+
+int security_path_chroot(struct path *path)
+{
+ return security_ops->path_chroot(path);
+}
#endif
int security_inode_create(struct inode *dir, struct dentry *dentry, int mode)
