gss_krb5: Remove VLA usage of skcipher

In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 46 insertions, 41 deletions

diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index 0220e1ca5280..4f43383971ba 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -53,7 +53,7 @@
 
 u32
 krb5_encrypt(
-	struct crypto_skcipher *tfm,
+	struct crypto_sync_skcipher *tfm,
 	void * iv,
 	void * in,
 	void * out,
@@ -62,24 +62,24 @@ krb5_encrypt(
 	u32 ret = -EINVAL;
 	struct scatterlist sg[1];
 	u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
-	SKCIPHER_REQUEST_ON_STACK(req, tfm);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
 
-	if (length % crypto_skcipher_blocksize(tfm) != 0)
+	if (length % crypto_sync_skcipher_blocksize(tfm) != 0)
 		goto out;
 
-	if (crypto_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
+	if (crypto_sync_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
 		dprintk("RPC:       gss_k5encrypt: tfm iv size too large %d\n",
-			crypto_skcipher_ivsize(tfm));
+			crypto_sync_skcipher_ivsize(tfm));
 		goto out;
 	}
 
 	if (iv)
-		memcpy(local_iv, iv, crypto_skcipher_ivsize(tfm));
+		memcpy(local_iv, iv, crypto_sync_skcipher_ivsize(tfm));
 
 	memcpy(out, in, length);
 	sg_init_one(sg, out, length);
 
-	skcipher_request_set_tfm(req, tfm);
+	skcipher_request_set_sync_tfm(req, tfm);
 	skcipher_request_set_callback(req, 0, NULL, NULL);
 	skcipher_request_set_crypt(req, sg, sg, length, local_iv);
 
@@ -92,7 +92,7 @@ out:
 
 u32
 krb5_decrypt(
-     struct crypto_skcipher *tfm,
+     struct crypto_sync_skcipher *tfm,
      void * iv,
      void * in,
      void * out,
@@ -101,23 +101,23 @@ krb5_decrypt(
 	u32 ret = -EINVAL;
 	struct scatterlist sg[1];
 	u8 local_iv[GSS_KRB5_MAX_BLOCKSIZE] = {0};
-	SKCIPHER_REQUEST_ON_STACK(req, tfm);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
 
-	if (length % crypto_skcipher_blocksize(tfm) != 0)
+	if (length % crypto_sync_skcipher_blocksize(tfm) != 0)
 		goto out;
 
-	if (crypto_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
+	if (crypto_sync_skcipher_ivsize(tfm) > GSS_KRB5_MAX_BLOCKSIZE) {
 		dprintk("RPC:       gss_k5decrypt: tfm iv size too large %d\n",
-			crypto_skcipher_ivsize(tfm));
+			crypto_sync_skcipher_ivsize(tfm));
 		goto out;
 	}
 	if (iv)
-		memcpy(local_iv,iv, crypto_skcipher_ivsize(tfm));
+		memcpy(local_iv, iv, crypto_sync_skcipher_ivsize(tfm));
 
 	memcpy(out, in, length);
 	sg_init_one(sg, out, length);
 
-	skcipher_request_set_tfm(req, tfm);
+	skcipher_request_set_sync_tfm(req, tfm);
 	skcipher_request_set_callback(req, 0, NULL, NULL);
 	skcipher_request_set_crypt(req, sg, sg, length, local_iv);
 
@@ -466,7 +466,8 @@ encryptor(struct scatterlist *sg, void *data)
 {
 	struct encryptor_desc *desc = data;
 	struct xdr_buf *outbuf = desc->outbuf;
-	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(desc->req);
+	struct crypto_sync_skcipher *tfm =
+		crypto_sync_skcipher_reqtfm(desc->req);
 	struct page *in_page;
 	int thislen = desc->fraglen + sg->length;
 	int fraglen, ret;
@@ -492,7 +493,7 @@ encryptor(struct scatterlist *sg, void *data)
 	desc->fraglen += sg->length;
 	desc->pos += sg->length;
 
-	fraglen = thislen & (crypto_skcipher_blocksize(tfm) - 1);
+	fraglen = thislen & (crypto_sync_skcipher_blocksize(tfm) - 1);
 	thislen -= fraglen;
 
 	if (thislen == 0)
@@ -526,16 +527,16 @@ encryptor(struct scatterlist *sg, void *data)
 }
 
 int
-gss_encrypt_xdr_buf(struct crypto_skcipher *tfm, struct xdr_buf *buf,
+gss_encrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *buf,
 		    int offset, struct page **pages)
 {
 	int ret;
 	struct encryptor_desc desc;
-	SKCIPHER_REQUEST_ON_STACK(req, tfm);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
 
-	BUG_ON((buf->len - offset) % crypto_skcipher_blocksize(tfm) != 0);
+	BUG_ON((buf->len - offset) % crypto_sync_skcipher_blocksize(tfm) != 0);
 
-	skcipher_request_set_tfm(req, tfm);
+	skcipher_request_set_sync_tfm(req, tfm);
 	skcipher_request_set_callback(req, 0, NULL, NULL);
 
 	memset(desc.iv, 0, sizeof(desc.iv));
@@ -567,7 +568,8 @@ decryptor(struct scatterlist *sg, void *data)
 {
 	struct decryptor_desc *desc = data;
 	int thislen = desc->fraglen + sg->length;
-	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(desc->req);
+	struct crypto_sync_skcipher *tfm =
+		crypto_sync_skcipher_reqtfm(desc->req);
 	int fraglen, ret;
 
 	/* Worst case is 4 fragments: head, end of page 1, start
@@ -578,7 +580,7 @@ decryptor(struct scatterlist *sg, void *data)
 	desc->fragno++;
 	desc->fraglen += sg->length;
 
-	fraglen = thislen & (crypto_skcipher_blocksize(tfm) - 1);
+	fraglen = thislen & (crypto_sync_skcipher_blocksize(tfm) - 1);
 	thislen -= fraglen;
 
 	if (thislen == 0)
@@ -608,17 +610,17 @@ decryptor(struct scatterlist *sg, void *data)
 }
 
 int
-gss_decrypt_xdr_buf(struct crypto_skcipher *tfm, struct xdr_buf *buf,
+gss_decrypt_xdr_buf(struct crypto_sync_skcipher *tfm, struct xdr_buf *buf,
 		    int offset)
 {
 	int ret;
 	struct decryptor_desc desc;
-	SKCIPHER_REQUEST_ON_STACK(req, tfm);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(req, tfm);
 
 	/* XXXJBF: */
-	BUG_ON((buf->len - offset) % crypto_skcipher_blocksize(tfm) != 0);
+	BUG_ON((buf->len - offset) % crypto_sync_skcipher_blocksize(tfm) != 0);
 
-	skcipher_request_set_tfm(req, tfm);
+	skcipher_request_set_sync_tfm(req, tfm);
 	skcipher_request_set_callback(req, 0, NULL, NULL);
 
 	memset(desc.iv, 0, sizeof(desc.iv));
@@ -672,12 +674,12 @@ xdr_extend_head(struct xdr_buf *buf, unsigned int base, unsigned int shiftlen)
 }
 
 static u32
-gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf,
+gss_krb5_cts_crypt(struct crypto_sync_skcipher *cipher, struct xdr_buf *buf,
 		   u32 offset, u8 *iv, struct page **pages, int encrypt)
 {
 	u32 ret;
 	struct scatterlist sg[1];
-	SKCIPHER_REQUEST_ON_STACK(req, cipher);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(req, cipher);
 	u8 *data;
 	struct page **save_pages;
 	u32 len = buf->len - offset;
@@ -706,7 +708,7 @@ gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf,
 
 	sg_init_one(sg, data, len);
 
-	skcipher_request_set_tfm(req, cipher);
+	skcipher_request_set_sync_tfm(req, cipher);
 	skcipher_request_set_callback(req, 0, NULL, NULL);
 	skcipher_request_set_crypt(req, sg, sg, len, iv);
 
@@ -735,7 +737,7 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 	struct xdr_netobj hmac;
 	u8 *cksumkey;
 	u8 *ecptr;
-	struct crypto_skcipher *cipher, *aux_cipher;
+	struct crypto_sync_skcipher *cipher, *aux_cipher;
 	int blocksize;
 	struct page **save_pages;
 	int nblocks, nbytes;
@@ -754,7 +756,7 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 		cksumkey = kctx->acceptor_integ;
 		usage = KG_USAGE_ACCEPTOR_SEAL;
 	}
-	blocksize = crypto_skcipher_blocksize(cipher);
+	blocksize = crypto_sync_skcipher_blocksize(cipher);
 
 	/* hide the gss token header and insert the confounder */
 	offset += GSS_KRB5_TOK_HDR_LEN;
@@ -807,7 +809,7 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 	memset(desc.iv, 0, sizeof(desc.iv));
 
 	if (cbcbytes) {
-		SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
+		SYNC_SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
 
 		desc.pos = offset + GSS_KRB5_TOK_HDR_LEN;
 		desc.fragno = 0;
@@ -816,7 +818,7 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 		desc.outbuf = buf;
 		desc.req = req;
 
-		skcipher_request_set_tfm(req, aux_cipher);
+		skcipher_request_set_sync_tfm(req, aux_cipher);
 		skcipher_request_set_callback(req, 0, NULL, NULL);
 
 		sg_init_table(desc.infrags, 4);
@@ -855,7 +857,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
 	struct xdr_buf subbuf;
 	u32 ret = 0;
 	u8 *cksum_key;
-	struct crypto_skcipher *cipher, *aux_cipher;
+	struct crypto_sync_skcipher *cipher, *aux_cipher;
 	struct xdr_netobj our_hmac_obj;
 	u8 our_hmac[GSS_KRB5_MAX_CKSUM_LEN];
 	u8 pkt_hmac[GSS_KRB5_MAX_CKSUM_LEN];
@@ -874,7 +876,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
 		cksum_key = kctx->initiator_integ;
 		usage = KG_USAGE_INITIATOR_SEAL;
 	}
-	blocksize = crypto_skcipher_blocksize(cipher);
+	blocksize = crypto_sync_skcipher_blocksize(cipher);
 
 
 	/* create a segment skipping the header and leaving out the checksum */
@@ -891,13 +893,13 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
 	memset(desc.iv, 0, sizeof(desc.iv));
 
 	if (cbcbytes) {
-		SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
+		SYNC_SKCIPHER_REQUEST_ON_STACK(req, aux_cipher);
 
 		desc.fragno = 0;
 		desc.fraglen = 0;
 		desc.req = req;
 
-		skcipher_request_set_tfm(req, aux_cipher);
+		skcipher_request_set_sync_tfm(req, aux_cipher);
 		skcipher_request_set_callback(req, 0, NULL, NULL);
 
 		sg_init_table(desc.frags, 4);
@@ -946,7 +948,8 @@ out_err:
  * Set the key of the given cipher.
  */
 int
-krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
+krb5_rc4_setup_seq_key(struct krb5_ctx *kctx,
+		       struct crypto_sync_skcipher *cipher,
 		       unsigned char *cksum)
 {
 	struct crypto_shash *hmac;
@@ -994,7 +997,7 @@ krb5_rc4_setup_seq_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
 	if (err)
 		goto out_err;
 
-	err = crypto_skcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
+	err = crypto_sync_skcipher_setkey(cipher, Kseq, kctx->gk5e->keylength);
 	if (err)
 		goto out_err;
 
@@ -1012,7 +1015,8 @@ out_err:
  * Set the key of cipher kctx->enc.
  */
 int
-krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
+krb5_rc4_setup_enc_key(struct krb5_ctx *kctx,
+		       struct crypto_sync_skcipher *cipher,
 		       s32 seqnum)
 {
 	struct crypto_shash *hmac;
@@ -1069,7 +1073,8 @@ krb5_rc4_setup_enc_key(struct krb5_ctx *kctx, struct crypto_skcipher *cipher,
 	if (err)
 		goto out_err;
 
-	err = crypto_skcipher_setkey(cipher, Kcrypt, kctx->gk5e->keylength);
+	err = crypto_sync_skcipher_setkey(cipher, Kcrypt,
+					  kctx->gk5e->keylength);
 	if (err)
 		goto out_err;