From: David Howells <dhowells@xxxxxxxxxx>
commit 911b79cde95c7da0ec02f48105358a36636b7a71 upstream.
[Please apply to 3.18-stable and 4.1-stable.]
If request_key() is used to find a keyring, only do the search part - don't
do the construction part if the keyring was not found by the search. We
don't really want keyrings in the negative instantiated state since the
rejected/negative instantiation error value in the payload is unioned with
keyring metadata.
Now the kernel gives an error:
request_key("keyring", "#selinux,bdekeyring", "keyring", KEY_SPEC_USER_SESSION_KEYRING) = -1 EPERM (Operation not permitted)
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
security/keys/request_key.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 486ef6fa393b..0d6253124278 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -440,6 +440,9 @@ static struct key *construct_key_and_link(struct keyring_search_context *ctx,
kenter("");
+ if (ctx->index_key.type == &key_type_keyring)
+ return ERR_PTR(-EPERM);
+
user = key_user_lookup(current_fsuid());
if (!user)
return ERR_PTR(-ENOMEM);
--
2.15.1.504.g5279b80103-goog