From: Eric Biggers <ebiggers@kernel.org>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
"open list:HARDWARE RANDOM NUMBER GENERATOR CORE"
<linux-crypto@vger.kernel.org>
Subject: Re: crypto: skcipher - Unmap pages after an external error
Date: Tue, 3 Sep 2019 08:50:20 -0500 [thread overview]
Message-ID: <20190903135020.GB5144@zzz.localdomain> (raw)
In-Reply-To: <20190903065438.GA9372@gondor.apana.org.au>
On Tue, Sep 03, 2019 at 04:54:38PM +1000, Herbert Xu wrote:
> int skcipher_walk_done(struct skcipher_walk *walk, int err)
> {
> - unsigned int n; /* bytes processed */
> - bool more;
> -
> - if (unlikely(err < 0))
> - goto finish;
> + unsigned int n = walk->nbytes - err;
> + unsigned int nbytes;
>
> - n = walk->nbytes - err;
> - walk->total -= n;
> - more = (walk->total != 0);
> + nbytes = walk->total - n;
>
> - if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
> - SKCIPHER_WALK_SLOW |
> - SKCIPHER_WALK_COPY |
> - SKCIPHER_WALK_DIFF)))) {
> + if (unlikely(err < 0)) {
> + nbytes = 0;
> + n = 0;
> + } else if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
> + SKCIPHER_WALK_SLOW |
> + SKCIPHER_WALK_COPY |
> + SKCIPHER_WALK_DIFF)))) {
> unmap_src:
> skcipher_unmap_src(walk);
> } else if (walk->flags & SKCIPHER_WALK_DIFF) {
> @@ -134,25 +134,34 @@ int skcipher_walk_done(struct skcipher_walk *walk, int err)
> * the algorithm requires it.
> */
> err = -EINVAL;
> - goto finish;
> - }
> - skcipher_done_slow(walk, n);
> - goto already_advanced;
> + nbytes = 0;
> + } else
> + n = skcipher_done_slow(walk, n);
> }
>
> + if (err > 0)
> + err = 0;
> +
> + walk->total = nbytes;
> + walk->nbytes = nbytes;
> +
> scatterwalk_advance(&walk->in, n);
> scatterwalk_advance(&walk->out, n);
> -already_advanced:
> - scatterwalk_done(&walk->in, 0, more);
> - scatterwalk_done(&walk->out, 1, more);
> + scatterwalk_done(&walk->in, 0, nbytes);
> + scatterwalk_done(&walk->out, 1, nbytes);
>
> - if (more) {
> + if (nbytes) {
> crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
> CRYPTO_TFM_REQ_MAY_SLEEP : 0);
> return skcipher_walk_next(walk);
> }
> - err = 0;
> -finish:
> +
> + return skcipher_walk_unwind(walk, err);
> +}
> +EXPORT_SYMBOL_GPL(skcipher_walk_done);
Doesn't this re-introduce the same bug that my patch fixed -- that
scatterwalk_done() could be called after 0 bytes processed, causing a crash in
scatterwalk_pagedone()?
- Eric
next prev parent reply other threads:[~2019-09-03 13:50 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 14:32 [PATCH 00/17] crypto: arm/aes - XTS ciphertext stealing and other updates Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 01/17] crypto: arm/aes - fix round key prototypes Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 02/17] crypto: arm/aes-ce - yield the SIMD unit between scatterwalk steps Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 03/17] crypto: arm/aes-ce - switch to 4x interleave Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 04/17] crypto: arm/aes-ce - replace tweak mask literal with composition Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 05/17] crypto: arm/aes-neonbs " Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 06/17] crypto: arm64/aes-neonbs " Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 07/17] crypto: arm64/aes-neon - limit exposed routines if faster driver is enabled Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 08/17] crypto: skcipher - add the ability to abort a skcipher walk Ard Biesheuvel
2019-08-30 8:03 ` Herbert Xu
2019-08-31 18:01 ` Ard Biesheuvel
2019-09-03 6:54 ` crypto: skcipher - Unmap pages after an external error Herbert Xu
2019-09-03 7:05 ` crypto: ablkcipher " Herbert Xu
2019-09-03 7:09 ` crypto: blkcipher " Herbert Xu
2019-09-03 13:50 ` Eric Biggers [this message]
2019-09-03 22:36 ` crypto: skcipher " Herbert Xu
2019-09-05 5:22 ` Eric Biggers
2019-09-05 5:40 ` Herbert Xu
2019-09-06 1:57 ` Eric Biggers
2019-09-06 2:15 ` Herbert Xu
2019-09-06 3:13 ` [v2 PATCH] " Herbert Xu
2019-09-07 0:52 ` Ard Biesheuvel
2019-09-07 1:19 ` Herbert Xu
2019-09-07 1:32 ` Ard Biesheuvel
2019-09-07 1:56 ` Herbert Xu
2019-09-07 2:14 ` Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 09/17] crypto: arm64/aes-cts-cbc-ce - performance tweak Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 10/17] crypto: arm64/aes-cts-cbc - move request context data to the stack Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 11/17] crypto: arm64/aes - implement support for XTS ciphertext stealing Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 12/17] crypto: arm64/aes-neonbs - implement ciphertext stealing for XTS Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 13/17] crypto: arm/aes-ce " Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 14/17] crypto: arm/aes-neonbs " Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 15/17] crypto: arm/aes-ce - implement ciphertext stealing for CBC Ard Biesheuvel
2019-09-30 16:32 ` Guenter Roeck
2019-09-30 18:19 ` Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 16/17] crypto: testmgr - add test vectors for XTS ciphertext stealing Ard Biesheuvel
2019-08-21 14:32 ` [PATCH 17/17] crypto: testmgr - Add additional AES-XTS vectors for covering CTS Ard Biesheuvel
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