From: Haiyue Wang <haiyue.wang@intel.com>
Date: Wed, 14 Jul 2021 15:34:59 +0800
Subject: gve: fix the wrong AdminQ buffer overflow check
Patch-mainline: v5.15-rc1
Git-commit: 63a9192b8fa1ea55efeba1f18fad52bb24d9bf12
References: bsc#1176940
The 'tail' pointer is also free-running count, so it needs to be masked
as 'adminq_prod_cnt' does, to become an index value of AdminQ buffer.
Fixes: 5cdad90de62c ("gve: Batch AQ commands for creating and destroying queues.")
Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Reviewed-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/google/gve/gve_adminq.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/google/gve/gve_adminq.c
+++ b/drivers/net/ethernet/google/gve/gve_adminq.c
@@ -322,7 +322,8 @@ static int gve_adminq_issue_cmd(struct g
tail = ioread32be(&priv->reg_bar0->adminq_event_counter);
// Check if next command will overflow the buffer.
- if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) == tail) {
+ if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) ==
+ (tail & priv->adminq_mask)) {
int err;
// Flush existing commands to make room.
@@ -332,7 +333,8 @@ static int gve_adminq_issue_cmd(struct g
// Retry.
tail = ioread32be(&priv->reg_bar0->adminq_event_counter);
- if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) == tail) {
+ if (((priv->adminq_prod_cnt + 1) & priv->adminq_mask) ==
+ (tail & priv->adminq_mask)) {
// This should never happen. We just flushed the
// command queue so there should be enough space.
return -ENOMEM;