From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25541C49ED7 for ; Fri, 20 Sep 2019 14:37:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EC34A20B7C for ; Fri, 20 Sep 2019 14:37:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392760AbfITOhY (ORCPT ); Fri, 20 Sep 2019 10:37:24 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35894 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388075AbfITOZB (ORCPT ); Fri, 20 Sep 2019 10:25:01 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqE-0004xJ-1W; Fri, 20 Sep 2019 15:24:58 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqD-0007rS-5L; Fri, 20 Sep 2019 15:24:57 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Herbert Xu" , "Eric Biggers" , "Greg Kroah-Hartman" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 036/132] crypto: salsa20 - don't access already-freed walk.iv In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit edaf28e996af69222b2cb40455dbb5459c2b875a upstream. If the user-provided IV needs to be aligned to the algorithm's alignmask, then skcipher_walk_virt() copies the IV into a new aligned buffer walk.iv. But skcipher_walk_virt() can fail afterwards, and then if the caller unconditionally accesses walk.iv, it's a use-after-free. salsa20-generic doesn't set an alignmask, so currently it isn't affected by this despite unconditionally accessing walk.iv. However this is more subtle than desired, and it was actually broken prior to the alignmask being removed by commit b62b3db76f73 ("crypto: salsa20-generic - cleanup and convert to skcipher API"). Since salsa20-generic does not update the IV and does not need any IV alignment, update it to use req->iv instead of walk.iv. Fixes: 2407d60872dd ("[CRYPTO] salsa20: Salsa20 stream cipher") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- crypto/salsa20_generic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/crypto/salsa20_generic.c +++ b/crypto/salsa20_generic.c @@ -186,7 +186,7 @@ static int encrypt(struct blkcipher_desc blkcipher_walk_init(&walk, dst, src, nbytes); err = blkcipher_walk_virt_block(desc, &walk, 64); - salsa20_ivsetup(ctx, walk.iv); + salsa20_ivsetup(ctx, desc->info); while (walk.nbytes >= 64) { salsa20_encrypt_bytes(ctx, walk.dst.virt.addr,