crypto: ccree - Correctly handle return of sg_nents_for_len

Fix error handling in cc_map_hash_request_update where sg_nents_for_len
return value was assigned to u32, converting negative errors to large
positive values before passing to sg_copy_to_buffer.

Check sg_nents_for_len return value and propagate errors before
assigning to areq_ctx->in_nents.

Fixes: b7ec853 ("crypto: ccree - use std api when possible")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Author: ISCAS-Vulab

drivers/crypto/ccree/cc_buffer_mgr.c

@@ -1235,6 +1235,7 @@ int cc_map_hash_request_update(struct cc_drvdata *drvdata, void *ctx,
 	int rc = 0;
 	u32 dummy = 0;
 	u32 mapped_nents = 0;
+	int sg_nents;
 
 	dev_dbg(dev, " update params : curr_buff=%p curr_buff_cnt=0x%X nbytes=0x%X src=%p curr_index=%u\n",
 		curr_buff, *curr_buff_cnt, nbytes, src, areq_ctx->buff_index);
@@ -1248,7 +1249,10 @@ int cc_map_hash_request_update(struct cc_drvdata *drvdata, void *ctx,
 	if (total_in_len < block_size) {
 		dev_dbg(dev, " less than one block: curr_buff=%p *curr_buff_cnt=0x%X copy_to=%p\n",
 			curr_buff, *curr_buff_cnt, &curr_buff[*curr_buff_cnt]);
-		areq_ctx->in_nents = sg_nents_for_len(src, nbytes);
+		sg_nents = sg_nents_for_len(src, nbytes);
+		if (sg_nents < 0)
+			return sg_nents;
+		areq_ctx->in_nents = sg_nents;
 		sg_copy_to_buffer(src, areq_ctx->in_nents,
 				  &curr_buff[*curr_buff_cnt], nbytes);
 		*curr_buff_cnt += nbytes;