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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Aashay Shringarpure <aashay@google.com>,
        Yi Chou <yich@google.com>,
        Shervin Oloumi <enlightened@google.com>,
        Grant Grundler <grundler@chromium.org>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 41/44] net: atlantic: verify hw_head_ lies within TX buffer ring
Date:   Mon, 23 May 2022 19:05:25 +0200
Message-Id: <20220523165800.814384078@linuxfoundation.org>
In-Reply-To: <20220523165752.797318097@linuxfoundation.org>
References: <20220523165752.797318097@linuxfoundation.org>
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From: Grant Grundler <grundler@chromium.org>

[ Upstream commit 2120b7f4d128433ad8c5f503a9584deba0684901 ]

Bounds check hw_head index provided by NIC to verify it lies
within the TX buffer ring.

Reported-by: Aashay Shringarpure <aashay@google.com>
Reported-by: Yi Chou <yich@google.com>
Reported-by: Shervin Oloumi <enlightened@google.com>
Signed-off-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c
index c4f914a29c38..bdb0b37c048a 100644
--- a/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c
+++ b/drivers/net/ethernet/aquantia/atlantic/hw_atl/hw_atl_b0.c
@@ -637,6 +637,13 @@ static int hw_atl_b0_hw_ring_tx_head_update(struct aq_hw_s *self,
 		err = -ENXIO;
 		goto err_exit;
 	}
+
+	/* Validate that the new hw_head_ is reasonable. */
+	if (hw_head_ >= ring->size) {
+		err = -ENXIO;
+		goto err_exit;
+	}
+
 	ring->hw_head = hw_head_;
 	err = aq_hw_err_from_flags(self);
 
-- 
2.35.1