crypto: nx - Moving NX-AES-GCM to be processed logic

The previous limits were estimated locally in a single step
basead on bound values, however it was not correct since
when given certain scatterlist the function nx_build_sg_lists
was consuming more sg entries than allocated causing a
memory corruption and crashes.

This patch removes the old logic and replace it into nx_sg_build_lists
in order to build a correct nx_sg list using the correct sg_max limit
and bounds.

Signed-off-by: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/nx/nx-aes-gcm.c b/drivers/crypto/nx/nx-aes-gcm.c
index 025d9a8..88c5624 100644 (file)
--- a/drivers/crypto/nx/nx-aes-gcm.c
+++ b/drivers/crypto/nx/nx-aes-gcm.c
@@ -131,7 +131,7 @@ static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
        struct nx_sg *nx_sg = nx_ctx->in_sg;
        unsigned int nbytes = req->assoclen;
        unsigned int processed = 0, to_process;
-       u32 max_sg_len;
+       unsigned int max_sg_len;
 
        if (nbytes <= AES_BLOCK_SIZE) {
                scatterwalk_start(&walk, req->assoc);
@@ -143,8 +143,10 @@ static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
        NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_CONTINUATION;
 
        /* page_limit: number of sg entries that fit on one page */
-       max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
+       max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
                           nx_ctx->ap->sglen);
+       max_sg_len = min_t(u64, max_sg_len,
+                          nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 
        do {
                /*
@@ -156,13 +158,14 @@ static int nx_gca(struct nx_crypto_ctx  *nx_ctx,
                to_process = min_t(u64, to_process,
                                   NX_PAGE_SIZE * (max_sg_len - 1));
 
+               nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
+                                         req->assoc, processed, &to_process);
+
                if ((to_process + processed) < nbytes)
                        NX_CPB_FDM(csbcpb_aead) |= NX_FDM_INTERMEDIATE;
                else
                        NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_INTERMEDIATE;
 
-               nx_sg = nx_walk_and_build(nx_ctx->in_sg, nx_ctx->ap->sglen,
-                                         req->assoc, processed, to_process);
                nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg)
                                        * sizeof(struct nx_sg);
 
@@ -195,7 +198,7 @@ static int gmac(struct aead_request *req, struct blkcipher_desc *desc)
        struct nx_sg *nx_sg;
        unsigned int nbytes = req->assoclen;
        unsigned int processed = 0, to_process;
-       u32 max_sg_len;
+       unsigned int max_sg_len;
 
        /* Set GMAC mode */
        csbcpb->cpb.hdr.mode = NX_MODE_AES_GMAC;
@@ -203,8 +206,10 @@ static int gmac(struct aead_request *req, struct blkcipher_desc *desc)
        NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION;
 
        /* page_limit: number of sg entries that fit on one page */
-       max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
+       max_sg_len = min_t(u64, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
                           nx_ctx->ap->sglen);
+       max_sg_len = min_t(u64, max_sg_len,
+                          nx_ctx->ap->databytelen/NX_PAGE_SIZE);
 
        /* Copy IV */
        memcpy(csbcpb->cpb.aes_gcm.iv_or_cnt, desc->info, AES_BLOCK_SIZE);
@@ -219,13 +224,14 @@ static int gmac(struct aead_request *req, struct blkcipher_desc *desc)
                to_process = min_t(u64, to_process,
                                   NX_PAGE_SIZE * (max_sg_len - 1));
 
+               nx_sg = nx_walk_and_build(nx_ctx->in_sg, max_sg_len,
+                                         req->assoc, processed, &to_process);
+
                if ((to_process + processed) < nbytes)
                        NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
                else
                        NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
 
-               nx_sg = nx_walk_and_build(nx_ctx->in_sg, nx_ctx->ap->sglen,
-                                         req->assoc, processed, to_process);
                nx_ctx->op.inlen = (nx_ctx->in_sg - nx_sg)
                                        * sizeof(struct nx_sg);
 
@@ -264,6 +270,7 @@ static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc,
        struct nx_csbcpb *csbcpb = nx_ctx->csbcpb;
        char out[AES_BLOCK_SIZE];
        struct nx_sg *in_sg, *out_sg;
+       int len;
 
        /* For scenarios where the input message is zero length, AES CTR mode
         * may be used. Set the source data to be a single block (16B) of all
@@ -279,11 +286,22 @@ static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc,
        else
                NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT;
 
+       len = AES_BLOCK_SIZE;
+
        /* Encrypt the counter/IV */
        in_sg = nx_build_sg_list(nx_ctx->in_sg, (u8 *) desc->info,
-                                AES_BLOCK_SIZE, nx_ctx->ap->sglen);
-       out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) out, sizeof(out),
+                                &len, nx_ctx->ap->sglen);
+
+       if (len != AES_BLOCK_SIZE)
+               return -EINVAL;
+
+       len = sizeof(out);
+       out_sg = nx_build_sg_list(nx_ctx->out_sg, (u8 *) out, &len,
                                  nx_ctx->ap->sglen);
+
+       if (len != sizeof(out))
+               return -EINVAL;
+
        nx_ctx->op.inlen = (nx_ctx->in_sg - in_sg) * sizeof(struct nx_sg);
        nx_ctx->op.outlen = (nx_ctx->out_sg - out_sg) * sizeof(struct nx_sg);
 
@@ -317,7 +335,6 @@ static int gcm_aes_nx_crypt(struct aead_request *req, int enc)
        unsigned int nbytes = req->cryptlen;
        unsigned int processed = 0, to_process;
        unsigned long irq_flags;
-       u32 max_sg_len;
        int rc = -EINVAL;
 
        spin_lock_irqsave(&nx_ctx->lock, irq_flags);
@@ -354,33 +371,24 @@ static int gcm_aes_nx_crypt(struct aead_request *req, int enc)
                nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req));
        }
 
-       /* page_limit: number of sg entries that fit on one page */
-       max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg),
-                          nx_ctx->ap->sglen);
-
        do {
-               /*
-                * to_process: the data chunk to process in this update.
-                * This value is bound by sg list limits.
-                */
-               to_process = min_t(u64, nbytes - processed,
-                                  nx_ctx->ap->databytelen);
-               to_process = min_t(u64, to_process,
-                                  NX_PAGE_SIZE * (max_sg_len - 1));
-
-               if ((to_process + processed) < nbytes)
-                       NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
-               else
-                       NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
+               to_process = nbytes - processed;
 
                csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8;
                desc.tfm = (struct crypto_blkcipher *) req->base.tfm;
                rc = nx_build_sg_lists(nx_ctx, &desc, req->dst,
-                                      req->src, to_process, processed,
+                                      req->src, &to_process, processed,
                                       csbcpb->cpb.aes_gcm.iv_or_cnt);
+
                if (rc)
                        goto out;
 
+               if ((to_process + processed) < nbytes)
+                       NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE;
+               else
+                       NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE;
+
+
                rc = nx_hcall_sync(nx_ctx, &nx_ctx->op,
                                   req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP);
                if (rc)