From d6e4e0f46e27a5eae66ce436b522c7602accf346 Mon Sep 17 00:00:00 2001
From: David Marchand <david.marchand@redhat.com>
Date: Wed, 22 Jun 2022 17:30:20 +0200
Subject: [PATCH] vhost/crypto: fix descriptor processing

[ upstream commit 2fbada91545c004f04449500af0c6276900317ab ]

copy_data was returning a pointer to an increased (off by one) descriptor.
Subsequent calls to copy_data in the library were then failing.
Fix this by incrementing the descriptor only if there is some left data
to copy.

Fixes: 4414bb67010d ("vhost/crypto: fix build with GCC 12")

Reported-by: Jakub Poczatek <jakub.poczatek@intel.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Tested-by: Jakub Poczatek <jakub.poczatek@intel.com>
Acked-by: Fan Zhang <roy.fan.zhang@intel.com>
---
 lib/vhost/vhost_crypto.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/vhost/vhost_crypto.c b/lib/vhost/vhost_crypto.c
index 293960d350..7d1d6a1861 100644
--- a/lib/vhost/vhost_crypto.c
+++ b/lib/vhost/vhost_crypto.c
@@ -610,8 +610,7 @@ copy_data(void *data, struct vhost_crypto_data_req *vc_req,
 			return -1;
 		left -= copied;
 		data = RTE_PTR_ADD(data, copied);
-		desc++;
-	} while (desc < head + max_n_descs && left != 0);
+	} while (left != 0 && ++desc < head + max_n_descs);
 
 	if (unlikely(left != 0))
 		return -1;
-- 
2.23.0