From: Lin Ma <linma@zju.edu.cn>
Date: Thu, 7 Oct 2021 17:44:30 +0000 (+0200)
Subject: nfc: nci: fix the UAF of rf_conn_info object
X-Git-Tag: v4.4.290~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1d5e0107bfdbef6cc140fb5d7a1a817a40948528;p=thirdparty%2Fkernel%2Fstable.git

nfc: nci: fix the UAF of rf_conn_info object

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>
---

diff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c
index 9b6eb913d801b..74e4d5e8c2752 100644
--- a/net/nfc/nci/rsp.c
+++ b/net/nfc/nci/rsp.c
@@ -274,6 +274,8 @@ static void nci_core_conn_close_rsp_packet(struct nci_dev *ndev,
 		conn_info = nci_get_conn_info_by_conn_id(ndev, ndev->cur_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);
 		}
 	}