From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754058AbcIMH4z (ORCPT ); Tue, 13 Sep 2016 03:56:55 -0400 Received: from mail-oi0-f54.google.com ([209.85.218.54]:35109 "EHLO mail-oi0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751574AbcIMH4w (ORCPT ); Tue, 13 Sep 2016 03:56:52 -0400 MIME-Version: 1.0 In-Reply-To: <20160913064329.GA26933@gondor.apana.org.au> References: <57D15BD3.40903@huawei.com> <20160908124709.GA26586@gondor.apana.org.au> <57D28CB8.4080904@huawei.com> <00B10D30F2BAA743B48953A4D86C96D54C8A8A@SZXEMI506-MBS.china.huawei.com> <20160913064329.GA26933@gondor.apana.org.au> From: Ard Biesheuvel Date: Tue, 13 Sep 2016 08:56:50 +0100 Message-ID: Subject: Re: Kernel panic - encryption/decryption failed when open file on Arm64 To: Herbert Xu Cc: liushuoran , Xiakaixu , "David S. Miller" , "Theodore Ts'o" , Jaegeuk Kim , "nhorman@tuxdriver.com" , "mh1@iki.fi" , "linux-crypto@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Wangbintian , Huxinwei , "zhangzhibin (C)" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13 September 2016 at 07:43, Herbert Xu wrote: > On Mon, Sep 12, 2016 at 06:40:15PM +0100, Ard Biesheuvel wrote: >> >> So to me, it seems like we should be taking the blkcipher_next_slow() >> path, which does a kmalloc() and bails with -ENOMEM if that fails. > > Indeed. This was broken a long time ago. It does seem to be > fixed in the new skcipher_walk code but here is a patch to fix > it for older kernels. > > ---8<--- > Subject: crypto: skcipher - Fix blkcipher walk OOM crash > > When we need to allocate a temporary blkcipher_walk_next and it > fails, the code is supposed to take the slow path of processing > the data block by block. However, due to an unrelated change > we instead end up dereferencing the NULL pointer. > > This patch fixes it by moving the unrelated bsize setting out > of the way so that we enter the slow path as inteded. > inteNded ^^^ > Fixes: 7607bd8ff03b ("[CRYPTO] blkcipher: Added blkcipher_walk_virt_block") > Cc: stable@vger.kernel.org > Reported-by: xiakaixu > Reported-by: Ard Biesheuvel > Signed-off-by: Herbert Xu > This fixes the issue for me Tested-by: Ard Biesheuvel I will follow up with fixes for the ARM and arm64 CTR code shortly. Thanks, Ard. > diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c > index 3699995..a832426 100644 > --- a/crypto/blkcipher.c > +++ b/crypto/blkcipher.c > @@ -233,6 +233,8 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc, > return blkcipher_walk_done(desc, walk, -EINVAL); > } > > + bsize = min(walk->walk_blocksize, n); > + > walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY | > BLKCIPHER_WALK_DIFF); > if (!scatterwalk_aligned(&walk->in, walk->alignmask) || > @@ -245,7 +247,6 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc, > } > } > > - bsize = min(walk->walk_blocksize, n); > n = scatterwalk_clamp(&walk->in, n); > n = scatterwalk_clamp(&walk->out, n); > > -- > Email: Herbert Xu > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt