From: Salvatore Benedetto Subject: [PATCH] crypto: rsa-pkcs1pad - Fix akcipher request allocation Date: Thu, 14 Jul 2016 11:25:05 +0100 Message-ID: <1468491905-2597-1-git-send-email-salvatore.benedetto@intel.com> Cc: linux-crypto@vger.kernel.org, Salvatore Benedetto To: herbert@gondor.apana.org.au, davem@davemloft.net, andrew.zaborowski@intel.com Return-path: Received: from mga02.intel.com ([134.134.136.20]:54659 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957AbcGNKZR (ORCPT ); Thu, 14 Jul 2016 06:25:17 -0400 Sender: linux-crypto-owner@vger.kernel.org List-ID: Embedding the akcipher_request in pkcs1pad_request don't take into account the context space required by the akcipher object. This result in memory corruption (and kernel panic) as the akcipher object will overwrite anything after akcipher_request structure. Fix it by dinamically allocating the structure with akcipher_request_alloc. Software akcipher implementation is working only because it is synchronous and it does not use a request context. Signed-off-by: Salvatore Benedetto --- crypto/rsa-pkcs1pad.c | 75 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 51 insertions(+), 24 deletions(-) diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c index 880d3db..d663ab6 100644 --- a/crypto/rsa-pkcs1pad.c +++ b/crypto/rsa-pkcs1pad.c @@ -101,7 +101,7 @@ struct pkcs1pad_inst_ctx { }; struct pkcs1pad_request { - struct akcipher_request child_req; + struct akcipher_request *child_req; struct scatterlist in_sg[2], out_sg[1]; uint8_t *in_buf, *out_buf; @@ -192,7 +192,7 @@ static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) if (err) goto out; - len = req_ctx->child_req.dst_len; + len = req_ctx->child_req->dst_len; pad_len = ctx->key_size - len; /* Four billion to one */ @@ -215,6 +215,7 @@ out: req->dst_len = ctx->key_size; kfree(req_ctx->in_buf); + akcipher_request_free(req_ctx->child_req); return err; } @@ -277,15 +278,21 @@ static int pkcs1pad_encrypt(struct akcipher_request *req) pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, ctx->key_size, NULL); - akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); - akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, + req_ctx->child_req = akcipher_request_alloc(ctx->child, GFP_KERNEL); + if (!req_ctx->child_req) { + kfree(req_ctx->out_buf); + kfree(req_ctx->in_buf); + return -ENOMEM; + } + akcipher_request_set_tfm(req_ctx->child_req, ctx->child); + akcipher_request_set_callback(req_ctx->child_req, req->base.flags, pkcs1pad_encrypt_sign_complete_cb, req); /* Reuse output buffer */ - akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg, + akcipher_request_set_crypt(req_ctx->child_req, req_ctx->in_sg, req->dst, ctx->key_size - 1, req->dst_len); - err = crypto_akcipher_encrypt(&req_ctx->child_req); + err = crypto_akcipher_encrypt(req_ctx->child_req); if (err != -EINPROGRESS && (err != -EBUSY || !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) @@ -308,7 +315,7 @@ static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) if (err) goto done; - if (req_ctx->child_req.dst_len != ctx->key_size - 1) { + if (req_ctx->child_req->dst_len != ctx->key_size - 1) { err = -EINVAL; goto done; } @@ -317,18 +324,18 @@ static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) err = -EINVAL; goto done; } - for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) + for (pos = 1; pos < req_ctx->child_req->dst_len; pos++) if (req_ctx->out_buf[pos] == 0x00) break; - if (pos < 9 || pos == req_ctx->child_req.dst_len) { + if (pos < 9 || pos == req_ctx->child_req->dst_len) { err = -EINVAL; goto done; } pos++; - if (req->dst_len < req_ctx->child_req.dst_len - pos) + if (req->dst_len < req_ctx->child_req->dst_len - pos) err = -EOVERFLOW; - req->dst_len = req_ctx->child_req.dst_len - pos; + req->dst_len = req_ctx->child_req->dst_len - pos; if (!err) sg_copy_from_buffer(req->dst, @@ -337,6 +344,7 @@ static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) done: kzfree(req_ctx->out_buf); + akcipher_request_free(req_ctx->child_req); return err; } @@ -373,16 +381,22 @@ static int pkcs1pad_decrypt(struct akcipher_request *req) pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, ctx->key_size, NULL); - akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); - akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, + req_ctx->child_req = akcipher_request_alloc(ctx->child, GFP_KERNEL); + if (!req_ctx->child_req) { + kfree(req_ctx->out_buf); + return -ENOMEM; + } + + akcipher_request_set_tfm(req_ctx->child_req, ctx->child); + akcipher_request_set_callback(req_ctx->child_req, req->base.flags, pkcs1pad_decrypt_complete_cb, req); /* Reuse input buffer, output to a new buffer */ - akcipher_request_set_crypt(&req_ctx->child_req, req->src, + akcipher_request_set_crypt(req_ctx->child_req, req->src, req_ctx->out_sg, req->src_len, ctx->key_size); - err = crypto_akcipher_decrypt(&req_ctx->child_req); + err = crypto_akcipher_decrypt(req_ctx->child_req); if (err != -EINPROGRESS && (err != -EBUSY || !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) @@ -420,6 +434,12 @@ static int pkcs1pad_sign(struct akcipher_request *req) if (!req_ctx->in_buf) return -ENOMEM; + req_ctx->child_req = akcipher_request_alloc(ctx->child, GFP_KERNEL); + if (!req_ctx->child_req) { + kfree(req_ctx->in_buf); + return -ENOMEM; + } + ps_end = ctx->key_size - digest_size - req->src_len - 2; req_ctx->in_buf[0] = 0x01; memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); @@ -431,15 +451,15 @@ static int pkcs1pad_sign(struct akcipher_request *req) pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, ctx->key_size - 1 - req->src_len, req->src); - akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); - akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, + akcipher_request_set_tfm(req_ctx->child_req, ctx->child); + akcipher_request_set_callback(req_ctx->child_req, req->base.flags, pkcs1pad_encrypt_sign_complete_cb, req); /* Reuse output buffer */ - akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg, + akcipher_request_set_crypt(req_ctx->child_req, req_ctx->in_sg, req->dst, ctx->key_size - 1, req->dst_len); - err = crypto_akcipher_sign(&req_ctx->child_req); + err = crypto_akcipher_sign(req_ctx->child_req); if (err != -EINPROGRESS && (err != -EBUSY || !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) @@ -464,7 +484,7 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) goto done; err = -EINVAL; - dst_len = req_ctx->child_req.dst_len; + dst_len = req_ctx->child_req->dst_len; if (dst_len < ctx->key_size - 1) goto done; @@ -507,6 +527,7 @@ static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) out_buf + pos, req->dst_len); done: kzfree(req_ctx->out_buf); + akcipher_request_free(req_ctx->child_req); return err; } @@ -551,16 +572,22 @@ static int pkcs1pad_verify(struct akcipher_request *req) pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, ctx->key_size, NULL); - akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); - akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, + req_ctx->child_req = akcipher_request_alloc(ctx->child, GFP_KERNEL); + if (!req_ctx->child_req) { + kfree(req_ctx->out_buf); + return -ENOMEM; + } + + akcipher_request_set_tfm(req_ctx->child_req, ctx->child); + akcipher_request_set_callback(req_ctx->child_req, req->base.flags, pkcs1pad_verify_complete_cb, req); /* Reuse input buffer, output to a new buffer */ - akcipher_request_set_crypt(&req_ctx->child_req, req->src, + akcipher_request_set_crypt(req_ctx->child_req, req->src, req_ctx->out_sg, req->src_len, ctx->key_size); - err = crypto_akcipher_verify(&req_ctx->child_req); + err = crypto_akcipher_verify(req_ctx->child_req); if (err != -EINPROGRESS && (err != -EBUSY || !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) -- 2.7.4