From b698a9f4c5c52317db486b069190c7e3d2b97e7e Mon Sep 17 00:00:00 2001
From: Gary R Hook <gary.hook@amd.com>
Date: Wed, 7 Mar 2018 11:31:14 -0600
Subject: [PATCH] crypto: ccp - Validate buffer lengths for copy operations
Git-commit: b698a9f4c5c52317db486b069190c7e3d2b97e7e
Patch-mainline: v4.17-rc1
References: bsc#1051510

The CCP driver copies data between scatter/gather lists and DMA buffers.
The length of the requested copy operation must be checked against
the available destination buffer length.

Reported-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/crypto/ccp/ccp-ops.c |  108 +++++++++++++++++++++++++++++++------------
 1 file changed, 78 insertions(+), 30 deletions(-)

--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -178,14 +178,18 @@ static int ccp_init_dm_workarea(struct c
 	return 0;
 }
 
-static void ccp_set_dm_area(struct ccp_dm_workarea *wa, unsigned int wa_offset,
-			    struct scatterlist *sg, unsigned int sg_offset,
-			    unsigned int len)
+static int ccp_set_dm_area(struct ccp_dm_workarea *wa, unsigned int wa_offset,
+			   struct scatterlist *sg, unsigned int sg_offset,
+			   unsigned int len)
 {
 	WARN_ON(!wa->address);
 
+	if (len > (wa->length - wa_offset))
+		return -EINVAL;
+
 	scatterwalk_map_and_copy(wa->address + wa_offset, sg, sg_offset, len,
 				 0);
+	return 0;
 }
 
 static void ccp_get_dm_area(struct ccp_dm_workarea *wa, unsigned int wa_offset,
@@ -205,8 +209,11 @@ static int ccp_reverse_set_dm_area(struc
 				   unsigned int len)
 {
 	u8 *p, *q;
+	int	rc;
 
-	ccp_set_dm_area(wa, wa_offset, sg, sg_offset, len);
+	rc = ccp_set_dm_area(wa, wa_offset, sg, sg_offset, len);
+	if (rc)
+		return rc;
 
 	p = wa->address + wa_offset;
 	q = p + len - 1;
@@ -509,7 +516,9 @@ static int ccp_run_aes_cmac_cmd(struct c
 		return ret;
 
 	dm_offset = CCP_SB_BYTES - aes->key_len;
-	ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	ret = ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	if (ret)
+		goto e_key;
 	ret = ccp_copy_to_sb(cmd_q, &key, op.jobid, op.sb_key,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
 	if (ret) {
@@ -528,7 +537,9 @@ static int ccp_run_aes_cmac_cmd(struct c
 		goto e_key;
 
 	dm_offset = CCP_SB_BYTES - AES_BLOCK_SIZE;
-	ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+	ret = ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+	if (ret)
+		goto e_ctx;
 	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
 	if (ret) {
@@ -556,8 +567,10 @@ static int ccp_run_aes_cmac_cmd(struct c
 				goto e_src;
 			}
 
-			ccp_set_dm_area(&ctx, 0, aes->cmac_key, 0,
-					aes->cmac_key_len);
+			ret = ccp_set_dm_area(&ctx, 0, aes->cmac_key, 0,
+					      aes->cmac_key_len);
+			if (ret)
+				goto e_src;
 			ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
 					     CCP_PASSTHRU_BYTESWAP_256BIT);
 			if (ret) {
@@ -666,7 +679,9 @@ static int ccp_run_aes_gcm_cmd(struct cc
 		return ret;
 
 	dm_offset = CCP_SB_BYTES - aes->key_len;
-	ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	ret = ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	if (ret)
+		goto e_key;
 	ret = ccp_copy_to_sb(cmd_q, &key, op.jobid, op.sb_key,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
 	if (ret) {
@@ -685,7 +700,9 @@ static int ccp_run_aes_gcm_cmd(struct cc
 		goto e_key;
 
 	dm_offset = CCP_AES_CTX_SB_COUNT * CCP_SB_BYTES - aes->iv_len;
-	ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+	ret = ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+	if (ret)
+		goto e_ctx;
 
 	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
@@ -777,7 +794,9 @@ static int ccp_run_aes_gcm_cmd(struct cc
 		goto e_dst;
 	}
 
-	ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+	ret = ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+	if (ret)
+		goto e_dst;
 
 	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
@@ -820,7 +839,9 @@ static int ccp_run_aes_gcm_cmd(struct cc
 					   DMA_BIDIRECTIONAL);
 		if (ret)
 			goto e_tag;
-		ccp_set_dm_area(&tag, 0, p_tag, 0, AES_BLOCK_SIZE);
+		ret = ccp_set_dm_area(&tag, 0, p_tag, 0, AES_BLOCK_SIZE);
+		if (ret)
+			goto e_tag;
 
 		ret = memcmp(tag.address, final_wa.address, AES_BLOCK_SIZE);
 		ccp_dm_free(&tag);
@@ -914,7 +935,9 @@ static int ccp_run_aes_cmd(struct ccp_cm
 		return ret;
 
 	dm_offset = CCP_SB_BYTES - aes->key_len;
-	ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	ret = ccp_set_dm_area(&key, dm_offset, aes->key, 0, aes->key_len);
+	if (ret)
+		goto e_key;
 	ret = ccp_copy_to_sb(cmd_q, &key, op.jobid, op.sb_key,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
 	if (ret) {
@@ -935,7 +958,9 @@ static int ccp_run_aes_cmd(struct ccp_cm
 	if (aes->mode != CCP_AES_MODE_ECB) {
 		/* Load the AES context - convert to LE */
 		dm_offset = CCP_SB_BYTES - AES_BLOCK_SIZE;
-		ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+		ret = ccp_set_dm_area(&ctx, dm_offset, aes->iv, 0, aes->iv_len);
+		if (ret)
+			goto e_ctx;
 		ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
 				     CCP_PASSTHRU_BYTESWAP_256BIT);
 		if (ret) {
@@ -1111,8 +1136,12 @@ static int ccp_run_xts_aes_cmd(struct cc
 		 * big endian to little endian.
 		 */
 		dm_offset = CCP_SB_BYTES - AES_KEYSIZE_128;
-		ccp_set_dm_area(&key, dm_offset, xts->key, 0, xts->key_len);
-		ccp_set_dm_area(&key, 0, xts->key, xts->key_len, xts->key_len);
+		ret = ccp_set_dm_area(&key, dm_offset, xts->key, 0, xts->key_len);
+		if (ret)
+			goto e_key;
+		ret = ccp_set_dm_area(&key, 0, xts->key, xts->key_len, xts->key_len);
+		if (ret)
+			goto e_key;
 	} else {
 		/* Version 5 CCPs use a 512-bit space for the key: each portion
 		 * occupies 256 bits, or one entire slot, and is zero-padded.
@@ -1121,9 +1150,13 @@ static int ccp_run_xts_aes_cmd(struct cc
 
 		dm_offset = CCP_SB_BYTES;
 		pad = dm_offset - xts->key_len;
-		ccp_set_dm_area(&key, pad, xts->key, 0, xts->key_len);
-		ccp_set_dm_area(&key, dm_offset + pad, xts->key, xts->key_len,
-				xts->key_len);
+		ret = ccp_set_dm_area(&key, pad, xts->key, 0, xts->key_len);
+		if (ret)
+			goto e_key;
+		ret = ccp_set_dm_area(&key, dm_offset + pad, xts->key,
+				      xts->key_len, xts->key_len);
+		if (ret)
+			goto e_key;
 	}
 	ret = ccp_copy_to_sb(cmd_q, &key, op.jobid, op.sb_key,
 			     CCP_PASSTHRU_BYTESWAP_256BIT);
@@ -1142,7 +1175,9 @@ static int ccp_run_xts_aes_cmd(struct cc
 	if (ret)
 		goto e_key;
 
-	ccp_set_dm_area(&ctx, 0, xts->iv, 0, xts->iv_len);
+	ret = ccp_set_dm_area(&ctx, 0, xts->iv, 0, xts->iv_len);
+	if (ret)
+		goto e_ctx;
 	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
 			     CCP_PASSTHRU_BYTESWAP_NOOP);
 	if (ret) {
@@ -1285,12 +1320,18 @@ static int ccp_run_des3_cmd(struct ccp_c
 	dm_offset = CCP_SB_BYTES - des3->key_len; /* Basic offset */
 
 	len_singlekey = des3->key_len / 3;
-	ccp_set_dm_area(&key, dm_offset + 2 * len_singlekey,
-			des3->key, 0, len_singlekey);
-	ccp_set_dm_area(&key, dm_offset + len_singlekey,
-			des3->key, len_singlekey, len_singlekey);
-	ccp_set_dm_area(&key, dm_offset,
-			des3->key, 2 * len_singlekey, len_singlekey);
+	ret = ccp_set_dm_area(&key, dm_offset + 2 * len_singlekey,
+			      des3->key, 0, len_singlekey);
+	if (ret)
+		goto e_key;
+	ret = ccp_set_dm_area(&key, dm_offset + len_singlekey,
+			      des3->key, len_singlekey, len_singlekey);
+	if (ret)
+		goto e_key;
+	ret = ccp_set_dm_area(&key, dm_offset,
+			      des3->key, 2 * len_singlekey, len_singlekey);
+	if (ret)
+		goto e_key;
 
 	/* Copy the key to the SB */
 	ret = ccp_copy_to_sb(cmd_q, &key, op.jobid, op.sb_key,
@@ -1318,7 +1359,10 @@ static int ccp_run_des3_cmd(struct ccp_c
 
 		/* Load the context into the LSB */
 		dm_offset = CCP_SB_BYTES - des3->iv_len;
-		ccp_set_dm_area(&ctx, dm_offset, des3->iv, 0, des3->iv_len);
+		ret = ccp_set_dm_area(&ctx, dm_offset, des3->iv, 0,
+				      des3->iv_len);
+		if (ret)
+			goto e_ctx;
 
 		if (cmd_q->ccp->vdata->version == CCP_VERSION(3, 0))
 			load_mode = CCP_PASSTHRU_BYTESWAP_NOOP;
@@ -1602,8 +1646,10 @@ static int ccp_run_sha_cmd(struct ccp_cm
 		}
 	} else {
 		/* Restore the context */
-		ccp_set_dm_area(&ctx, 0, sha->ctx, 0,
-				sb_count * CCP_SB_BYTES);
+		ret = ccp_set_dm_area(&ctx, 0, sha->ctx, 0,
+				      sb_count * CCP_SB_BYTES);
+		if (ret)
+			goto e_ctx;
 	}
 
 	ret = ccp_copy_to_sb(cmd_q, &ctx, op.jobid, op.sb_ctx,
@@ -1903,7 +1949,9 @@ static int ccp_run_passthru_cmd(struct c
 		if (ret)
 			return ret;
 
-		ccp_set_dm_area(&mask, 0, pt->mask, 0, pt->mask_len);
+		ret = ccp_set_dm_area(&mask, 0, pt->mask, 0, pt->mask_len);
+		if (ret)
+			goto e_mask;
 		ret = ccp_copy_to_sb(cmd_q, &mask, op.jobid, op.sb_key,
 				     CCP_PASSTHRU_BYTESWAP_NOOP);
 		if (ret) {
