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From: Herbert Xu <herbert@gondor.apana.org.au>
To: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Eric Biggers <ebiggers@google.com>, linux-crypto@vger.kernel.org
Subject: Re: [PATCH] crypto: pcrypt - forbid recursive instantiation
Date: Tue, 19 Nov 2019 20:53:33 +0800	[thread overview]
Message-ID: <20191119125333.xzfvclo2aiycvjsn@gondor.apana.org.au> (raw)
In-Reply-To: <20190920043556.GP2879@gauss3.secunet.de>

On Fri, Sep 20, 2019 at 06:35:56AM +0200, Steffen Klassert wrote:
>
> Fix this by making pcrypt forbid instantiation if pcrypt appears in the
> underlying ->cra_driver_name or if an underlying algorithm needs a
> fallback.  This is somewhat of a hack, but it's a simple fix that should
> be sufficient to prevent the deadlock.

This still doesn't resolve the case where pcrypt is used in a
non-transparent fashion, e.g., through a fallback.  Note that
even adding a NEED_FALLBACK flag won't fix this as you can construct
an instance on top of a NEED_FALLBACK algorithm that itself does
not need a fallback.

Anyway I decided to change pcrypt to use a set of queues per
instance rather than globally and it should resolve the problem.

Cheers,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

      reply	other threads:[~2019-11-19 12:53 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-20  4:35 [PATCH] crypto: pcrypt - forbid recursive instantiation Steffen Klassert
2019-11-19 12:53 ` Herbert Xu [this message]

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