From: David Howells Date: Mon, 19 Oct 2015 10:20:28 +0000 (+0100) Subject: KEYS: Don't permit request_key() to construct a new keyring X-Git-Tag: v4.1.12-124.31.3~262 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3fa39ea26b570f0beaf9dca1a3ff7abff536b3db;p=users%2Fjedix%2Flinux-maple.git KEYS: Don't permit request_key() to construct a new keyring 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 (cherry picked from commit 911b79cde95c7da0ec02f48105358a36636b7a71) Orabug: 29304551 CVE: CVE-2017-17807 Reviewed-by: John Donnelly Signed-off-by: Allen Pais Signed-off-by: Brian Maly --- 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);