From 6d213fba7d617f1f1f3b94f40b36aad6849f5f69 Mon Sep 17 00:00:00 2001 From: Haiyue Wang Date: Wed, 14 Jul 2021 15:34:59 +0800 Subject: [PATCH] gve: fix the wrong AdminQ buffer overflow check [ Upstream commit 63a9192b8fa1ea55efeba1f18fad52bb24d9bf12 ] 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 Reviewed-by: Catherine Sullivan Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/google/gve/gve_adminq.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c index 53864f2005994..b175f2b2f5bcf 100644 --- a/drivers/net/ethernet/google/gve/gve_adminq.c +++ b/drivers/net/ethernet/google/gve/gve_adminq.c @@ -233,7 +233,8 @@ static int gve_adminq_issue_cmd(struct gve_priv *priv, 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. @@ -243,7 +244,8 @@ static int gve_adminq_issue_cmd(struct gve_priv *priv, // 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;