diff mbox

[v2,2/3] KEYS: don't revoke uninstantiated key in request_key_auth_new()

Message ID 20170921205742.144596-3-ebiggers3@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Biggers Sept. 21, 2017, 8:57 p.m. UTC 
From: Eric Biggers <ebiggers@google.com>

If key_instantiate_and_link() were to fail (which fortunately isn't
possible currently), the call to key_revoke(authkey) would crash with a
NULL pointer dereference in request_key_auth_revoke() because the key
has not yet been instantiated.

Fix this by removing the call to key_revoke().  key_put() is sufficient,
as it's not possible for an uninstantiated authkey to have been used for
anything yet.

Fixes: b5f545c880a2 ("[PATCH] keys: Permit running process to instantiate keys")
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 security/keys/request_key_auth.c | 1 -
 1 file changed, 1 deletion(-)

Comments

David Howells Sept. 25, 2017, 2:14 p.m. UTC | #1 
Eric Biggers <ebiggers3@gmail.com> wrote:

> Fix this by removing the call to key_revoke().  key_put() is sufficient,
> as it's not possible for an uninstantiated authkey to have been used for
> anything yet.

Note that the owner can call keyctl_describe() upon it, though that shouldn't
wait because KEY_LOOKUP_PARTIAL would be specified.

However, this is probably fair enough, and it should be gc'd quickly because
it'll lose its last ref.

David
--
To unsubscribe from this list: send the line "unsubscribe linux-security-module" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 8f12645945ca..2df92b619a38 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -220,7 +220,6 @@  struct key *request_key_auth_new(struct key *target, const void *callout_info,
 	return authkey;
 
 error_put_authkey:
-	key_revoke(authkey);
 	key_put(authkey);
 error_free_rka:
 	free_request_key_auth(rka);