Re: [PATCH] crypto: cmac - fix alignment of 'consts'
On Mon, Oct 10, 2016 at 10:15:15AM -0700, Eric Biggers wrote: > The per-transform 'consts' array is accessed as __be64 in > crypto_cmac_digest_setkey() but was only guaranteed to be aligned to > __alignof__(long). Fix this by aligning it to __alignof__(__be64). > > Signed-off-by: Eric Biggers Patch applied. Thanks. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] crypto: cmac - fix alignment of 'consts'
On Mon, Oct 10, 2016 at 10:51:14AM -0700, Joe Perches wrote: > > Hey Eric. > > I don't see any PTR_ALIGN uses in crypto/ or drivers/crypto/ that > use a bitwise or, just mask + 1, but I believe the effect is the > same. Anyway, your choice, but I think using min is clearer. > > cheers, Joe Usually the bitwise OR is used when setting cra_alignmask in the 'struct crypto_alg'. Indeed, the problem could be solved by setting inst->alg.base.cra_alignmask = alg->cra_alignmask | (__alignof__(__be64) - 1); I decided against that because it would always force 8-byte alignment for CMAC input buffers and keys, when in fact they don't need that level of alignment unless the underlying block cipher requires it. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] crypto: cmac - fix alignment of 'consts'
On Mon, 2016-10-10 at 10:37 -0700, Eric Biggers wrote: > On Mon, Oct 10, 2016 at 10:29:55AM -0700, Joe Perches wrote: > > On Mon, 2016-10-10 at 10:15 -0700, Eric Biggers wrote: > > > The per-transform 'consts' array is accessed as __be64 in > > > crypto_cmac_digest_setkey() but was only guaranteed to be aligned to > > > __alignof__(long). Fix this by aligning it to __alignof__(__be64). > > [] > > > diff --git a/crypto/cmac.c b/crypto/cmac.c > > [] > > > @@ -57,7 +57,8 @@ static int crypto_cmac_digest_setkey(struct > > > crypto_shash *parent, > > > unsigned long alignmask = crypto_shash_alignmask(parent); > > > struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent); > > > unsigned int bs = crypto_shash_blocksize(parent); > > > - __be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1); > > > + __be64 *consts = PTR_ALIGN((void *)ctx->ctx, > > > +(alignmask | (__alignof__(__be64) - 1)) + 1); > > > > > > Using a bitwise or looks very odd there. Perhaps: > > > > min(alignmask + 1, __alignof__(__be64)) > > > > > Alignment has to be a power of 2. From the code I've read, crypto drivers > work > with alignment a lot and use bitwise OR to mean "the more restrictive of these > alignmasks". So I believe the way it's written is the preferred style. > > Eric Hey Eric. I don't see any PTR_ALIGN uses in crypto/ or drivers/crypto/ that use a bitwise or, just mask + 1, but I believe the effect is the same. Anyway, your choice, but I think using min is clearer. cheers, Joe -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] crypto: cmac - fix alignment of 'consts'
On Mon, Oct 10, 2016 at 10:29:55AM -0700, Joe Perches wrote: > On Mon, 2016-10-10 at 10:15 -0700, Eric Biggers wrote: > > The per-transform 'consts' array is accessed as __be64 in > > crypto_cmac_digest_setkey() but was only guaranteed to be aligned to > > __alignof__(long). Fix this by aligning it to __alignof__(__be64). > [] > > diff --git a/crypto/cmac.c b/crypto/cmac.c > [] > > @@ -57,7 +57,8 @@ static int crypto_cmac_digest_setkey(struct crypto_shash > > *parent, > > unsigned long alignmask = crypto_shash_alignmask(parent); > > struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent); > > unsigned int bs = crypto_shash_blocksize(parent); > > - __be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1); > > + __be64 *consts = PTR_ALIGN((void *)ctx->ctx, > > + (alignmask | (__alignof__(__be64) - 1)) + 1); > > Using a bitwise or looks very odd there. Perhaps: > > min(alignmask + 1, __alignof__(__be64)) > Alignment has to be a power of 2. From the code I've read, crypto drivers work with alignment a lot and use bitwise OR to mean "the more restrictive of these alignmasks". So I believe the way it's written is the preferred style. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] crypto: cmac - fix alignment of 'consts'
On Mon, 2016-10-10 at 10:15 -0700, Eric Biggers wrote: > The per-transform 'consts' array is accessed as __be64 in > crypto_cmac_digest_setkey() but was only guaranteed to be aligned to > __alignof__(long). Fix this by aligning it to __alignof__(__be64). [] > diff --git a/crypto/cmac.c b/crypto/cmac.c [] > @@ -57,7 +57,8 @@ static int crypto_cmac_digest_setkey(struct crypto_shash > *parent, > unsigned long alignmask = crypto_shash_alignmask(parent); > struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent); > unsigned int bs = crypto_shash_blocksize(parent); > - __be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1); > + __be64 *consts = PTR_ALIGN((void *)ctx->ctx, > +(alignmask | (__alignof__(__be64) - 1)) + 1); Using a bitwise or looks very odd there. Perhaps: min(alignmask + 1, __alignof__(__be64)) -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH] crypto: cmac - fix alignment of 'consts'
The per-transform 'consts' array is accessed as __be64 in crypto_cmac_digest_setkey() but was only guaranteed to be aligned to __alignof__(long). Fix this by aligning it to __alignof__(__be64). Signed-off-by: Eric Biggers --- crypto/cmac.c | 13 + 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/crypto/cmac.c b/crypto/cmac.c index b6c4059..04080dc 100644 --- a/crypto/cmac.c +++ b/crypto/cmac.c @@ -57,7 +57,8 @@ static int crypto_cmac_digest_setkey(struct crypto_shash *parent, unsigned long alignmask = crypto_shash_alignmask(parent); struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent); unsigned int bs = crypto_shash_blocksize(parent); - __be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1); + __be64 *consts = PTR_ALIGN((void *)ctx->ctx, + (alignmask | (__alignof__(__be64) - 1)) + 1); u64 _const[2]; int i, err = 0; u8 msb_mask, gfmask; @@ -173,7 +174,8 @@ static int crypto_cmac_digest_final(struct shash_desc *pdesc, u8 *out) struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc); struct crypto_cipher *tfm = tctx->child; int bs = crypto_shash_blocksize(parent); - u8 *consts = PTR_ALIGN((void *)tctx->ctx, alignmask + 1); + u8 *consts = PTR_ALIGN((void *)tctx->ctx, + (alignmask | (__alignof__(__be64) - 1)) + 1); u8 *odds = PTR_ALIGN((void *)ctx->ctx, alignmask + 1); u8 *prev = odds + bs; unsigned int offset = 0; @@ -258,7 +260,8 @@ static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb) if (err) goto out_free_inst; - alignmask = alg->cra_alignmask | (sizeof(long) - 1); + /* We access the data as u32s when xoring. */ + alignmask = alg->cra_alignmask | (__alignof__(u32) - 1); inst->alg.base.cra_alignmask = alignmask; inst->alg.base.cra_priority = alg->cra_priority; inst->alg.base.cra_blocksize = alg->cra_blocksize; @@ -270,7 +273,9 @@ static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb) + alg->cra_blocksize * 2; inst->alg.base.cra_ctxsize = - ALIGN(sizeof(struct cmac_tfm_ctx), alignmask + 1) + ALIGN(sizeof(struct cmac_tfm_ctx), crypto_tfm_ctx_alignment()) + + ((alignmask | (__alignof__(__be64) - 1)) & + ~(crypto_tfm_ctx_alignment() - 1)) + alg->cra_blocksize * 2; inst->alg.base.cra_init = cmac_init_tfm; -- 2.8.0.rc3.226.g39d4020 -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
