1 files changed, 24 insertions, 17 deletions

diff --git a/crypto/rsa-pkcs1pad.c b/crypto/rsa-pkcs1pad.c
index 877019a6d3ea8..8baab4307f7b9 100644
--- a/crypto/rsa-pkcs1pad.c
+++ b/crypto/rsa-pkcs1pad.c
@@ -298,41 +298,48 @@ static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
+	unsigned int dst_len;
 	unsigned int pos;
-
-	if (err == -EOVERFLOW)
-		/* Decrypted value had no leading 0 byte */
-		err = -EINVAL;
+	u8 *out_buf;
 
 	if (err)
 		goto done;
 
-	if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
-		err = -EINVAL;
+	err = -EINVAL;
+	dst_len = req_ctx->child_req.dst_len;
+	if (dst_len < ctx->key_size - 1)
 		goto done;
+
+	out_buf = req_ctx->out_buf;
+	if (dst_len == ctx->key_size) {
+		if (out_buf[0] != 0x00)
+			/* Decrypted value had no leading 0 byte */
+			goto done;
+
+		dst_len--;
+		out_buf++;
 	}
 
-	if (req_ctx->out_buf[0] != 0x02) {
-		err = -EINVAL;
+	if (out_buf[0] != 0x02)
 		goto done;
-	}
-	for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
-		if (req_ctx->out_buf[pos] == 0x00)
+
+	for (pos = 1; pos < dst_len; pos++)
+		if (out_buf[pos] == 0x00)
 			break;
-	if (pos < 9 || pos == req_ctx->child_req.dst_len) {
-		err = -EINVAL;
+	if (pos < 9 || pos == dst_len)
 		goto done;
-	}
 	pos++;
 
-	if (req->dst_len < req_ctx->child_req.dst_len - pos)
+	err = 0;
+
+	if (req->dst_len < dst_len - pos)
 		err = -EOVERFLOW;
-	req->dst_len = req_ctx->child_req.dst_len - pos;
+	req->dst_len = dst_len - pos;
 
 	if (!err)
 		sg_copy_from_buffer(req->dst,
 				sg_nents_for_len(req->dst, req->dst_len),
-				req_ctx->out_buf + pos, req->dst_len);
+				out_buf + pos, req->dst_len);
 
 done:
 	kzfree(req_ctx->out_buf);