From: Boris Pismenny <borisp@mellanox.com>
Date: Fri, 13 Jul 2018 14:33:44 +0300
Subject: tls: Fix zerocopy_from_iter iov handling
Patch-mainline: v4.19-rc1
Git-commit: 4718799817c5a30ae723eda21f3a6c7d8701b1a4
References: bsc#1109837

zerocopy_from_iter iterates over the message, but it doesn't revert the
updates made by the iov iteration. This patch fixes it. Now, the iov can
be used after calling zerocopy_from_iter.

Fixes: 3c4d75591 ("tls: kernel TLS support")
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/tls/tls_sw.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -263,7 +263,7 @@ static int zerocopy_from_iter(struct soc
 			      int length, int *pages_used,
 			      unsigned int *size_used,
 			      struct scatterlist *to, int to_max_pages,
-			      bool charge)
+			      bool charge, bool revert)
 {
 	struct page *pages[MAX_SKB_FRAGS];
 
@@ -314,6 +314,8 @@ static int zerocopy_from_iter(struct soc
 out:
 	*size_used = size;
 	*pages_used = num_elem;
+	if (revert)
+		iov_iter_revert(from, size);
 
 	return rc;
 }
@@ -415,7 +417,7 @@ alloc_encrypted:
 				&ctx->sg_plaintext_size,
 				ctx->sg_plaintext_data,
 				ARRAY_SIZE(ctx->sg_plaintext_data),
-				true);
+				true, false);
 			if (ret)
 				goto fallback_to_reg_send;
 
@@ -833,7 +835,7 @@ int tls_sw_recvmsg(struct sock *sk,
 				err = zerocopy_from_iter(sk, &msg->msg_iter,
 							 to_copy, &pages,
 							 &chunk, &sgin[1],
-							 MAX_SKB_FRAGS,	false);
+							 MAX_SKB_FRAGS,	false, true);
 				if (err < 0)
 					goto fallback_to_reg_recv;