From: Stephan =?ISO-8859-1?Q?M=FCller?= Subject: Re: BUG: Seems un-initialed dst pointer received from algif_aead when outlen is zero Date: Tue, 21 Mar 2017 12:43:02 +0100 Message-ID: <3894659.2TbsNqkGul@tauon.atsec.com> References: <5047201.43uXAH9qJG@positron.chronox.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Cc: linux-crypto@vger.kernel.org, Herbert Xu To: Harsh Jain Return-path: Received: from mail.eperm.de ([89.247.134.16]:58194 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932242AbdCULnN (ORCPT ); Tue, 21 Mar 2017 07:43:13 -0400 In-Reply-To: Sender: linux-crypto-owner@vger.kernel.org List-ID: Am Dienstag, 21. M?rz 2017, 11:59:54 CET schrieb Harsh Jain: Hi Harsh, > > Executing this command on a 4.9 kernel, I get: > > > > bin/kcapi -x 2 -c "gcm(aes)" -i 0d92aa861746b324f20ee6b7 -k > > f4a6a5e5f2066f6dd9ec6fc5169c29043560ef595c9e81e76f42d29212cc581c -a "" -t > > "5f24c68cbe6f32c29652442bf5d483ad" -q "" > > EBADMSG > > Probably because s/w implementation is not trying to access dst sg > pointer because there's nothing to copy in destination buffer. 1 > question If we don't have data to copy to destination buffer what > should dst pointer contains? The dst SGL should simply be discarded by implementations in the case you mention above. The implementation receives the tag size and the supplied input buffer. If that input buffer length is equal to the tag length (i.e. no AAD and no ciphertext), why would the dst SGL be ever touched during decrytion? Ciao Stephan