Patch-mainline: v5.12-rc1
Git-commit: 3194a1746e8aabe86075fd3c5e7cf1f4632d7f16
References: XSA-362 CVE-2021-26931 bsc#1181753
From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 15 Feb 2021 08:55:31 +0100
Subject: [PATCH 7/9] xen-netback: don't "handle" error by BUG()

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 drivers/net/xen-netback/netback.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index b8100298017b..fcaf4dd9d9c4 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1328,13 +1328,11 @@ int xenvif_tx_action(struct xenvif_queue *queue, int budget)
 		return 0;
 
 	gnttab_batch_copy(queue->tx_copy_ops, nr_cops);
-	if (nr_mops != 0) {
+	if (nr_mops != 0)
 		ret = gnttab_map_refs(queue->tx_map_ops,
 				      NULL,
 				      queue->pages_to_map,
 				      nr_mops);
-		BUG_ON(ret);
-	}
 
 	work_done = xenvif_tx_submit(queue);
 
-- 
2.26.2