# \[PATCH AUTOSEL 4.14 4/9\] nfc: nci: fix the UAF of rf\_conn\_info object

- From: Sasha Levin \<sashal@kernel.org\>
- Date: 2021-10-21 00:25:08 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/10/1548964
- Thread: https://ratatoskr.run/stable/2021/10/1548958/t.md

```text
From: Lin Ma <redacted>

[ Upstream commit 1b1499a817c90fd1ce9453a2c98d2a01cca0e775 ]

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 <redacted>
Signed-off-by: Lin Ma <redacted>
Signed-off-by: Krzysztof Kozlowski <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/nfc/nci/rsp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/nfc/nci/rsp.c b/net/nfc/nci/rsp.c
index e3bbf1937d0e..7681f89dc312 100644
--- a/net/nfc/nci/rsp.c
+++ b/net/nfc/nci/rsp.c
@@ -289,6 +289,8 @@ static void nci_core_conn_close_rsp_packet(struct nci_dev *ndev,
 							 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);
 		}
 	}
-- 
2.33.0

```