From: Sowmini Varadhan Subject: Re: unaligned access in pkcs7_verify Date: Mon, 12 Oct 2015 09:46:27 -0400 Message-ID: <20151012134627.GG14646@oracle.com> References: <20151002140014.GI18263@oracle.com> <20151008131519.GA24362@gondor.apana.org.au> <20151008144343.GE19655@oracle.com> <20151012133209.GA27746@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dhowells@redhat.com, linux-crypto@vger.kernel.org, "David S. Miller" To: Herbert Xu Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:32772 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752473AbbJLNql (ORCPT ); Mon, 12 Oct 2015 09:46:41 -0400 Content-Disposition: inline In-Reply-To: <20151012133209.GA27746@gondor.apana.org.au> Sender: linux-crypto-owner@vger.kernel.org List-ID: On (10/12/15 21:32), Herbert Xu wrote: > Thanks. We have two bugs here. First of all pkcs7_verify definitely > shouldn't place the structure after the digest without aligning the > pointer. So something like your patch is needed (but please use > alignof instead of sizeof). Also don't put in digest_size but > instead align the pointer like > > desc = PTR_ALIGN(digest + digest_size, ...) That patch might not be rock-solid by itself though. I was seeing some panics/crashes when I was running with that patch, so I backed it off temporarily - should sinfo->sig.digest_size be set to the aligned value? > The sparc sha algorithms themselves need to declare the alignment > that they require. Currently they claim to be able to handle any > alignment which appears to not be the case. How would one do that correctly? I'm not a crypto expert, but I can help test the patch.. --Sowmini