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-rw-r--r--security/keys/key.c1
-rw-r--r--security/keys/keyctl.c24
-rw-r--r--security/keys/request_key.c48
3 files changed, 47 insertions, 26 deletions
diff --git a/security/keys/key.c b/security/keys/key.c
index 66049183ad89..d97c9394b5dd 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -833,7 +833,6 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
key_check(keyring);
- key_ref = ERR_PTR(-EPERM);
if (!(flags & KEY_ALLOC_BYPASS_RESTRICTION))
restrict_link = keyring->restrict_link;
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 76d22f726ae4..1ffe60bb2845 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1588,9 +1588,8 @@ error_keyring:
* The caller must have Setattr permission to change keyring restrictions.
*
* The requested type name may be a NULL pointer to reject all attempts
- * to link to the keyring. If _type is non-NULL, _restriction can be
- * NULL or a pointer to a string describing the restriction. If _type is
- * NULL, _restriction must also be NULL.
+ * to link to the keyring. In this case, _restriction must also be NULL.
+ * Otherwise, both _type and _restriction must be non-NULL.
*
* Returns 0 if successful.
*/
@@ -1598,7 +1597,6 @@ long keyctl_restrict_keyring(key_serial_t id, const char __user *_type,
const char __user *_restriction)
{
key_ref_t key_ref;
- bool link_reject = !_type;
char type[32];
char *restriction = NULL;
long ret;
@@ -1607,31 +1605,29 @@ long keyctl_restrict_keyring(key_serial_t id, const char __user *_type,
if (IS_ERR(key_ref))
return PTR_ERR(key_ref);
+ ret = -EINVAL;
if (_type) {
- ret = key_get_type_from_user(type, _type, sizeof(type));
- if (ret < 0)
+ if (!_restriction)
goto error;
- }
- if (_restriction) {
- if (!_type) {
- ret = -EINVAL;
+ ret = key_get_type_from_user(type, _type, sizeof(type));
+ if (ret < 0)
goto error;
- }
restriction = strndup_user(_restriction, PAGE_SIZE);
if (IS_ERR(restriction)) {
ret = PTR_ERR(restriction);
goto error;
}
+ } else {
+ if (_restriction)
+ goto error;
}
- ret = keyring_restrict(key_ref, link_reject ? NULL : type, restriction);
+ ret = keyring_restrict(key_ref, _type ? type : NULL, restriction);
kfree(restriction);
-
error:
key_ref_put(key_ref);
-
return ret;
}
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index e8036cd0ad54..114f7408feee 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -251,11 +251,12 @@ static int construct_key(struct key *key, const void *callout_info,
* The keyring selected is returned with an extra reference upon it which the
* caller must release.
*/
-static void construct_get_dest_keyring(struct key **_dest_keyring)
+static int construct_get_dest_keyring(struct key **_dest_keyring)
{
struct request_key_auth *rka;
const struct cred *cred = current_cred();
struct key *dest_keyring = *_dest_keyring, *authkey;
+ int ret;
kenter("%p", dest_keyring);
@@ -264,6 +265,8 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
/* the caller supplied one */
key_get(dest_keyring);
} else {
+ bool do_perm_check = true;
+
/* use a default keyring; falling through the cases until we
* find one that we actually have */
switch (cred->jit_keyring) {
@@ -278,8 +281,10 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
dest_keyring =
key_get(rka->dest_keyring);
up_read(&authkey->sem);
- if (dest_keyring)
+ if (dest_keyring) {
+ do_perm_check = false;
break;
+ }
}
case KEY_REQKEY_DEFL_THREAD_KEYRING:
@@ -314,11 +319,29 @@ static void construct_get_dest_keyring(struct key **_dest_keyring)
default:
BUG();
}
+
+ /*
+ * Require Write permission on the keyring. This is essential
+ * because the default keyring may be the session keyring, and
+ * joining a keyring only requires Search permission.
+ *
+ * However, this check is skipped for the "requestor keyring" so
+ * that /sbin/request-key can itself use request_key() to add
+ * keys to the original requestor's destination keyring.
+ */
+ if (dest_keyring && do_perm_check) {
+ ret = key_permission(make_key_ref(dest_keyring, 1),
+ KEY_NEED_WRITE);
+ if (ret) {
+ key_put(dest_keyring);
+ return ret;
+ }
+ }
}
*_dest_keyring = dest_keyring;
kleave(" [dk %d]", key_serial(dest_keyring));
- return;
+ return 0;
}
/*
@@ -444,11 +467,15 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
if (ctx->index_key.type == &key_type_keyring)
return ERR_PTR(-EPERM);
- user = key_user_lookup(current_fsuid());
- if (!user)
- return ERR_PTR(-ENOMEM);
+ ret = construct_get_dest_keyring(&dest_keyring);
+ if (ret)
+ goto error;
- construct_get_dest_keyring(&dest_keyring);
+ user = key_user_lookup(current_fsuid());
+ if (!user) {
+ ret = -ENOMEM;
+ goto error_put_dest_keyring;
+ }
ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key);
key_user_put(user);
@@ -463,7 +490,7 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
} else if (ret == -EINPROGRESS) {
ret = 0;
} else {
- goto couldnt_alloc_key;
+ goto error_put_dest_keyring;
}
key_put(dest_keyring);
@@ -473,8 +500,9 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
construction_failed:
key_negate_and_link(key, key_negative_timeout, NULL, NULL);
key_put(key);
-couldnt_alloc_key:
+error_put_dest_keyring:
key_put(dest_keyring);
+error:
kleave(" = %d", ret);
return ERR_PTR(ret);
}
@@ -546,9 +574,7 @@ struct key *request_key_and_link(struct key_type *type,
if (!IS_ERR(key_ref)) {
key = key_ref_to_ptr(key_ref);
if (dest_keyring) {
- construct_get_dest_keyring(&dest_keyring);
ret = key_link(dest_keyring, key);
- key_put(dest_keyring);
if (ret < 0) {
key_put(key);
key = ERR_PTR(ret);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 20:46:55 +0000