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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 CC62FC07E85 for ; Sun, 9 Dec 2018 22:25:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E75120661 for ; Sun, 9 Dec 2018 22:25:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9E75120661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728520AbeLIWZO (ORCPT ); Sun, 9 Dec 2018 17:25:14 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34920 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726451AbeLIVzQ (ORCPT ); Sun, 9 Dec 2018 16:55:16 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW72e-0002ia-PO; Sun, 09 Dec 2018 21:55:12 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72b-0003LD-TK; Sun, 09 Dec 2018 21:55:09 +0000 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, "Herbert Xu" , "Liu Chao" , "Eric Biggers" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 100/328] crypto: ablkcipher - fix crash flushing dcache in error path In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 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 3.16.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit 318abdfbe708aaaa652c79fb500e9bd60521f9dc upstream. Like the skcipher_walk and blkcipher_walk cases: scatterwalk_done() is only meant to be called after a nonzero number of bytes have been processed, since scatterwalk_pagedone() will flush the dcache of the *previous* page. But in the error case of ablkcipher_walk_done(), e.g. if the input wasn't an integer number of blocks, scatterwalk_done() was actually called after advancing 0 bytes. This caused a crash ("BUG: unable to handle kernel paging request") during '!PageSlab(page)' on architectures like arm and arm64 that define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was page-aligned as in that case walk->offset == 0. Fix it by reorganizing ablkcipher_walk_done() to skip the scatterwalk_advance() and scatterwalk_done() if an error has occurred. Reported-by: Liu Chao Fixes: bf06099db18a ("crypto: skcipher - Add ablkcipher_walk interfaces") Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings --- crypto/ablkcipher.c | 57 +++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 31 deletions(-) --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -72,11 +72,9 @@ static inline u8 *ablkcipher_get_spot(u8 return max(start, end_page); } -static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk, - unsigned int bsize) +static inline void ablkcipher_done_slow(struct ablkcipher_walk *walk, + unsigned int n) { - unsigned int n = bsize; - for (;;) { unsigned int len_this_page = scatterwalk_pagelen(&walk->out); @@ -88,17 +86,13 @@ static inline unsigned int ablkcipher_do n -= len_this_page; scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg)); } - - return bsize; } -static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk, - unsigned int n) +static inline void ablkcipher_done_fast(struct ablkcipher_walk *walk, + unsigned int n) { scatterwalk_advance(&walk->in, n); scatterwalk_advance(&walk->out, n); - - return n; } static int ablkcipher_walk_next(struct ablkcipher_request *req, @@ -108,39 +102,40 @@ int ablkcipher_walk_done(struct ablkciph struct ablkcipher_walk *walk, int err) { struct crypto_tfm *tfm = req->base.tfm; - unsigned int nbytes = 0; + unsigned int n; /* bytes processed */ + bool more; - if (likely(err >= 0)) { - unsigned int n = walk->nbytes - err; + if (unlikely(err < 0)) + goto finish; - if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) - n = ablkcipher_done_fast(walk, n); - else if (WARN_ON(err)) { + n = walk->nbytes - err; + walk->total -= n; + more = (walk->total != 0); + + if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW))) { + ablkcipher_done_fast(walk, n); + } else { + if (WARN_ON(err)) { + /* unexpected case; didn't process all bytes */ err = -EINVAL; - goto err; - } else - n = ablkcipher_done_slow(walk, n); - - nbytes = walk->total - n; - err = 0; + goto finish; + } + ablkcipher_done_slow(walk, n); } - scatterwalk_done(&walk->in, 0, nbytes); - scatterwalk_done(&walk->out, 1, nbytes); + scatterwalk_done(&walk->in, 0, more); + scatterwalk_done(&walk->out, 1, more); -err: - walk->total = nbytes; - walk->nbytes = nbytes; - - if (nbytes) { + if (more) { crypto_yield(req->base.flags); return ablkcipher_walk_next(req, walk); } - + err = 0; +finish: + walk->nbytes = 0; if (walk->iv != req->info) memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize); kfree(walk->iv_buffer); - return err; } EXPORT_SYMBOL_GPL(ablkcipher_walk_done);