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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,
        Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
        Lin Ma <linma@zju.edu.cn>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.14 17/30] nfc: nci: fix the UAF of rf_conn_info object
Date:   Mon, 25 Oct 2021 21:14:37 +0200
Message-Id: <20211025190927.150505682@linuxfoundation.org>
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From: Lin Ma <linma@zju.edu.cn>

commit 1b1499a817c90fd1ce9453a2c98d2a01cca0e775 upstream.

The nci_core_conn_close_rsp_packet() function will release the conn_info
with given conn_id. However, it needs to set the rf_conn_info to NULL to
prevent other routines like nci_rf_intf_activated_ntf_packet() to trigger
the UAF.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/nfc/nci/rsp.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/nfc/nci/rsp.c
+++ b/net/nfc/nci/rsp.c
@@ -289,6 +289,8 @@ static void nci_core_conn_close_rsp_pack
 							 ndev->cur_conn_id);
 		if (conn_info) {
 			list_del(&conn_info->list);
+			if (conn_info == ndev->rf_conn_info)
+				ndev->rf_conn_info = NULL;
 			devm_kfree(&ndev->nfc_dev->dev, conn_info);
 		}
 	}