Re: FAILED: patch "[PATCH] crypto: caam - strip input zeros from RSA input buffer" failed to apply to 4.9-stable tree

On Fri, Jun 15, 2018 at 09:07:24AM +0100, Martin Townsend wrote:

On Thu, Jun 14, 2018 at 2:08 PM gregkh@linuxfoundation.org wrote:

...

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8a2a0dd35f2e54c023d9041a5428b6c5639af86c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Horia=20Geant=C4=83?= horia.geanta@nxp.com Date: Mon, 16 Apr 2018 08:07:05 -0500 Subject: [PATCH] crypto: caam - strip input zeros from RSA input buffer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

Sometimes the provided RSA input buffer provided is not stripped of leading zeros. This could cause its size to be bigger than that of the modulus, making the HW complain:

caam_jr 2142000.jr1: 40000789: DECO: desc idx 7: Protocol Size Error - A protocol has seen an error in size. When running RSA, pdb size N < (size of F) when no formatting is used; or pdb size N < (F + 11) when formatting is used.

Fix the problem by stripping off the leading zero from input data before feeding it to the CAAM accelerator.

Fixes: 8c419778ab57e ("crypto: caam - add support for RSA algorithm") Cc: stable@vger.kernel.org # 4.8+ Reported-by: Martin Townsend mtownsend1973@gmail.com Link: https://lkml.kernel.org/r/CABatt_ytYORYKtApcB4izhNanEKkGFi9XAQMjHi_n-8YWoCRi... Signed-off-by: Horia Geantă horia.geanta@nxp.com Tested-by: Fabio Estevam fabio.estevam@nxp.com Reviewed-by: Tudor Ambarus tudor.ambarus@microchip.com Signed-off-by: Herbert Xu herbert@gondor.apana.org.au

diff --git a/drivers/crypto/caam/caampkc.c b/drivers/crypto/caam/caampkc.c index 7a897209f181..979072b25eaa 100644 --- a/drivers/crypto/caam/caampkc.c +++ b/drivers/crypto/caam/caampkc.c @@ -166,18 +166,71 @@ static void rsa_priv_f3_done(struct device *dev, u32 *desc, u32 err, akcipher_request_complete(req, err); }

+static int caam_rsa_count_leading_zeros(struct scatterlist *sgl,

•                                   unsigned int nbytes,
  

•                                   unsigned int flags)
  

+{

•   struct sg_mapping_iter miter;
  

•   int lzeros, ents;
  

•   unsigned int len;
  

•   unsigned int tbytes = nbytes;
  

•   const u8 *buff;
  

•   ents = sg_nents_for_len(sgl, nbytes);
  

•   if (ents < 0)
  

•           return ents;
  

•   sg_miter_start(&miter, sgl, ents, SG_MITER_FROM_SG | flags);
  

•   lzeros = 0;
  

•   len = 0;
  

•   while (nbytes > 0) {
  

•           while (len && !*buff) {
  

•                   lzeros++;
  

•                   len--;
  

•                   buff++;
  

•           }
  

•           if (len && *buff)
  

•                   break;
  

•           sg_miter_next(&miter);
  

•           buff = miter.addr;
  

•           len = miter.length;
  

•           nbytes -= lzeros;
  

•           lzeros = 0;
  

•   }
  

•   miter.consumed = lzeros;
  

•   sg_miter_stop(&miter);
  

•   nbytes -= lzeros;
  

•   return tbytes - nbytes;
  

+}

static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req, size_t desclen) { struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm); struct device *dev = ctx->dev;

•   struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
    struct rsa_edesc *edesc;
    gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
                   GFP_KERNEL : GFP_ATOMIC;
  

•   int sg_flags = (flags == GFP_ATOMIC) ? SG_MITER_ATOMIC : 0;
    int sgc;
    int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes;
    int src_nents, dst_nents;
  

•   int lzeros;
  

•   lzeros = caam_rsa_count_leading_zeros(req->src, req->src_len, sg_flags);
  

•   if (lzeros < 0)
  

•           return ERR_PTR(lzeros);
  

•   req->src_len -= lzeros;
  

•   req->src = scatterwalk_ffwd(req_ctx->src, req->src, lzeros);
  
    src_nents = sg_nents_for_len(req->src, req->src_len);
    dst_nents = sg_nents_for_len(req->dst, req->dst_len);
  

@@ -953,6 +1006,7 @@ static struct akcipher_alg caam_rsa = { .max_size = caam_rsa_max_size, .init = caam_rsa_init_tfm, .exit = caam_rsa_exit_tfm,

•   .reqsize = sizeof(struct caam_rsa_req_ctx),
    .base = {
            .cra_name = "rsa",
            .cra_driver_name = "rsa-caam",
  

diff --git a/drivers/crypto/caam/caampkc.h b/drivers/crypto/caam/caampkc.h index fd145c46eae1..82645bcf8b27 100644 --- a/drivers/crypto/caam/caampkc.h +++ b/drivers/crypto/caam/caampkc.h @@ -95,6 +95,14 @@ struct caam_rsa_ctx { struct device *dev; };

+/**

• • caam_rsa_req_ctx - per request context.
• • @src: input scatterlist (stripped of leading zeros)
• */

+struct caam_rsa_req_ctx {

•   struct scatterlist src[2];
  

+};

/**

• rsa_edesc - s/w-extended rsa descriptor
• @src_nents : number of segments in input scatterlist

I have back ported this to 4.9 and have it running on an i.MX6UL board. I am happy to submit this if someone can tell me the best way to do this.

Just send it to stable@vger.kernel.org and say "here is the backport to 4.9 of commit id XXXX, can you please apply it?"

nothing fancy needed :)

thanks,

greg k-h