[PATCH 4.20 088/145] crypto: cfb - fix decryption

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>

commit fa4600734b74f74d9169c3015946d4722f8bcf79 upstream.

crypto_cfb_decrypt_segment() incorrectly XOR'ed generated keystream with
IV, rather than with data stream, resulting in incorrect decryption.
Test vectors will be added in the next patch.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 crypto/cfb.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/crypto/cfb.c
+++ b/crypto/cfb.c
@@ -144,7 +144,7 @@ static int crypto_cfb_decrypt_segment(st
 
 	do {
 		crypto_cfb_encrypt_one(tfm, iv, dst);
-		crypto_xor(dst, iv, bsize);
+		crypto_xor(dst, src, bsize);
 		iv = src;
 
 		src += bsize;