linux-kernel - Re: [BUG] SLOB breaks Crypto

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4BF2EB66.4020207@codelabs.ch>
Date:	Tue, 18 May 2010 21:32:54 +0200
From:	Adrian-Ken Rueegsegger <ken@...elabs.ch>
To:	Herbert Xu <herbert@...dor.apana.org.au>
CC:	Matt Mackall <mpm@...enic.com>,
	Geert Uytterhoeven <geert@...ux-m68k.org>,
	michael-dev@...i-braun.de, Pekka Enberg <penberg@...helsinki.fi>,
	linux-kernel@...r.kernel.org, linux-crypto@...r.kernel.org,
	Atsushi Nemoto <anemo@....ocn.ne.jp>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [BUG] SLOB breaks Crypto

Herbert Xu wrote:
> On Tue, May 18, 2010 at 10:17:35AM +0200, Adrian-Ken Rueegsegger wrote:
>> As noted in my other mail [1] it seems like the HMAC tests trigger these
>> errors.
> 
> Thanks for all the detective work!
> 
> I think the problem is this changeset:
> 
> commit 6eb7228421c01ba48a6a88a7a5b3e71cfb70d4a9
> Author: Herbert Xu <herbert@...dor.apana.org.au>
> Date:   Tue Jan 8 17:16:44 2008 +1100
> 
>     [CRYPTO] api: Set default CRYPTO_MINALIGN to unsigned long long
>     
>     Thanks to David Miller for pointing out that the SLAB (or SLOB/SLUB)
>     cache uses the alignment of unsigned long long if the architecture
>     kmalloc/slab alignment macros are not defined.
>     
>     This patch changes the CRYPTO_MINALIGN so that it uses the same default
>     value.
>     
>     Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>
> 
> diff --git a/include/linux/crypto.h b/include/linux/crypto.h
> index 0aba104..5e02d1b 100644
> --- a/include/linux/crypto.h
> +++ b/include/linux/crypto.h
> @@ -90,13 +90,11 @@
>  #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
>  #elif defined(ARCH_SLAB_MINALIGN)
>  #define CRYPTO_MINALIGN ARCH_SLAB_MINALIGN
> +#else
> +#define CRYPTO_MINALIGN __alignof__(unsigned long long)
>  #endif
>  
> -#ifdef CRYPTO_MINALIGN
>  #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
> -#else
> -#define CRYPTO_MINALIGN_ATTR
> -#endif
>  
>  struct scatterlist;
>  struct crypto_ablkcipher;
> 
> So evidently the assumption made in this change does not work on
> SLOB since it only guarantees __alignof__(unsigned long).
> 
> I think the simplest fix is to revert this changeset.

When doing the revert it is necessary to either have
ARCH_KMALLOC_MINALIGN defined or explicitly define CRYPTO_MINALIGN in
the case where it is not. Otherwise shash compilation fails because it
needs CRYPTO_MINALIGN.

Regards,
Adrian
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/