Subject: [PATCH 01/23] gve: Fix the queue page list allocated pages count

From: Jeroen de Borst <[email-masked]>
Date: Tue, 26 Nov 2019 15:36:19 -0800

[ Upstream commit a95069ecb7092d03b2ea1c39ee04514fe9627540 ]

In gve_alloc_queue_page_list(), when a page allocation fails,
qpl->num_entries will be wrong.  In this case priv->num_registered_pages
can underflow in gve_free_queue_page_list(), causing subsequent calls
to gve_alloc_queue_page_list() to fail.

Fixes: f5cedc84a30d ("gve: Add transmit and receive support")
Signed-off-by: Jeroen de Borst <[email-masked]>
Reviewed-by: Catherine Sullivan <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/ethernet/google/gve/gve_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index aca95f64bde8..9b7a8db9860f 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -544,7 +544,7 @@ static int gve_alloc_queue_page_list(struct gve_priv *priv, u32 id,
 	}
 
 	qpl->id = id;
-	qpl->num_entries = pages;
+	qpl->num_entries = 0;
 	qpl->pages = kvzalloc(pages * sizeof(*qpl->pages), GFP_KERNEL);
 	/* caller handles clean up */
 	if (!qpl->pages)
@@ -562,6 +562,7 @@ static int gve_alloc_queue_page_list(struct gve_priv *priv, u32 id,
 		/* caller handles clean up */
 		if (err)
 			return -ENOMEM;
+		qpl->num_entries++;
 	}
 	priv->num_registered_pages += pages;
 
-- 
2.20.1