From d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 02:45:28 +0000
Subject: [PATCH] add boot partition size
---
kernel/kernel/user_namespace.c | 91 ++++++++++++++++++++++++++++++++++++---------
1 files changed, 72 insertions(+), 19 deletions(-)
diff --git a/kernel/kernel/user_namespace.c b/kernel/kernel/user_namespace.c
index 923414a..ce396ea 100644
--- a/kernel/kernel/user_namespace.c
+++ b/kernel/kernel/user_namespace.c
@@ -1,9 +1,4 @@
-/*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation, version 2 of the
- * License.
- */
+// SPDX-License-Identifier: GPL-2.0-only
#include <linux/export.h>
#include <linux/nsproxy.h>
@@ -111,6 +106,7 @@
if (!ns)
goto fail_dec;
+ ns->parent_could_setfcap = cap_raised(new->cap_effective, CAP_SETFCAP);
ret = ns_alloc_inum(&ns->ns);
if (ret)
goto fail_free;
@@ -133,8 +129,9 @@
ns->flags = parent_ns->flags;
mutex_unlock(&userns_state_mutex);
-#ifdef CONFIG_PERSISTENT_KEYRINGS
- init_rwsem(&ns->persistent_keyring_register_sem);
+#ifdef CONFIG_KEYS
+ INIT_LIST_HEAD(&ns->keyring_name_list);
+ init_rwsem(&ns->keyring_sem);
#endif
ret = -ENOMEM;
if (!setup_userns_sysctls(ns))
@@ -196,9 +193,7 @@
kfree(ns->projid_map.reverse);
}
retire_userns_sysctls(ns);
-#ifdef CONFIG_PERSISTENT_KEYRINGS
- key_put(ns->persistent_keyring_register);
-#endif
+ key_free_user_ns(ns);
ns_free_inum(&ns->ns);
kmem_cache_free(user_ns_cachep, ns);
dec_user_namespaces(ucounts);
@@ -521,7 +516,7 @@
*
* When there is no mapping defined for the user-namespace projid
* pair INVALID_PROJID is returned. Callers are expected to test
- * for and handle handle INVALID_PROJID being returned. INVALID_PROJID
+ * for and handle INVALID_PROJID being returned. INVALID_PROJID
* may be tested for using projid_valid().
*/
kprojid_t make_kprojid(struct user_namespace *ns, projid_t projid)
@@ -847,6 +842,60 @@
return 0;
}
+/**
+ * verify_root_map() - check the uid 0 mapping
+ * @file: idmapping file
+ * @map_ns: user namespace of the target process
+ * @new_map: requested idmap
+ *
+ * If a process requests mapping parent uid 0 into the new ns, verify that the
+ * process writing the map had the CAP_SETFCAP capability as the target process
+ * will be able to write fscaps that are valid in ancestor user namespaces.
+ *
+ * Return: true if the mapping is allowed, false if not.
+ */
+static bool verify_root_map(const struct file *file,
+ struct user_namespace *map_ns,
+ struct uid_gid_map *new_map)
+{
+ int idx;
+ const struct user_namespace *file_ns = file->f_cred->user_ns;
+ struct uid_gid_extent *extent0 = NULL;
+
+ for (idx = 0; idx < new_map->nr_extents; idx++) {
+ if (new_map->nr_extents <= UID_GID_MAP_MAX_BASE_EXTENTS)
+ extent0 = &new_map->extent[idx];
+ else
+ extent0 = &new_map->forward[idx];
+ if (extent0->lower_first == 0)
+ break;
+
+ extent0 = NULL;
+ }
+
+ if (!extent0)
+ return true;
+
+ if (map_ns == file_ns) {
+ /* The process unshared its ns and is writing to its own
+ * /proc/self/uid_map. User already has full capabilites in
+ * the new namespace. Verify that the parent had CAP_SETFCAP
+ * when it unshared.
+ * */
+ if (!file_ns->parent_could_setfcap)
+ return false;
+ } else {
+ /* Process p1 is writing to uid_map of p2, who is in a child
+ * user namespace to p1's. Verify that the opener of the map
+ * file has CAP_SETFCAP against the parent of the new map
+ * namespace */
+ if (!file_ns_capable(file, map_ns->parent, CAP_SETFCAP))
+ return false;
+ }
+
+ return true;
+}
+
static ssize_t map_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos,
int cap_setid,
@@ -854,7 +903,7 @@
struct uid_gid_map *parent_map)
{
struct seq_file *seq = file->private_data;
- struct user_namespace *ns = seq->private;
+ struct user_namespace *map_ns = seq->private;
struct uid_gid_map new_map;
unsigned idx;
struct uid_gid_extent extent;
@@ -901,7 +950,7 @@
/*
* Adjusting namespace settings requires capabilities on the target.
*/
- if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN))
+ if (cap_valid(cap_setid) && !file_ns_capable(file, map_ns, CAP_SYS_ADMIN))
goto out;
/* Parse the user data */
@@ -971,7 +1020,7 @@
ret = -EPERM;
/* Validate the user is allowed to use user id's mapped to. */
- if (!new_idmap_permitted(file, ns, cap_setid, &new_map))
+ if (!new_idmap_permitted(file, map_ns, cap_setid, &new_map))
goto out;
ret = -EPERM;
@@ -1092,6 +1141,10 @@
struct uid_gid_map *new_map)
{
const struct cred *cred = file->f_cred;
+
+ if (cap_setid == CAP_SETUID && !verify_root_map(file, ns, new_map))
+ return false;
+
/* Don't allow mappings that would allow anything that wouldn't
* be allowed without the establishment of unprivileged mappings.
*/
@@ -1259,7 +1312,7 @@
put_user_ns(to_user_ns(ns));
}
-static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns)
+static int userns_install(struct nsset *nsset, struct ns_common *ns)
{
struct user_namespace *user_ns = to_user_ns(ns);
struct cred *cred;
@@ -1280,14 +1333,14 @@
if (!ns_capable(user_ns, CAP_SYS_ADMIN))
return -EPERM;
- cred = prepare_creds();
+ cred = nsset_cred(nsset);
if (!cred)
- return -ENOMEM;
+ return -EINVAL;
put_user_ns(cred->user_ns);
set_cred_user_ns(cred, get_user_ns(user_ns));
- return commit_creds(cred);
+ return 0;
}
struct ns_common *ns_get_owner(struct ns_common *ns)
--
Gitblit v1.6.2