2022-01-23 14:53:27

by Soenke Huster

Subject: [PATCH] Bluetooth: msft: fix null pointer deref on msft_monitor_device_evt

msft_find_handle_data returns NULL if it can't find the handle.
Therefore, handle_data must be checked, otherwise a null pointer
is dereferenced.

Signed-off-by: Soenke Huster <[email protected]>
---
net/bluetooth/msft.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
index 484540855863..d2cf92e834f7 100644
--- a/net/bluetooth/msft.c
+++ b/net/bluetooth/msft.c
@@ -705,6 +705,9 @@ static void msft_monitor_device_evt(struct hci_dev *hdev, struct sk_buff *skb)

handle_data = msft_find_handle_data(hdev, ev->monitor_handle, false);

+ if (!handle_data)
+ return;
+
switch (ev->addr_type) {
case ADDR_LE_DEV_PUBLIC:
addr_type = BDADDR_LE_PUBLIC;
--
2.34.1

2022-01-23 15:39:52

by Marcel Holtmann

Subject: Re: [PATCH] Bluetooth: msft: fix null pointer deref on msft_monitor_device_evt

Hi Soenke,

> msft_find_handle_data returns NULL if it can't find the handle.
> Therefore, handle_data must be checked, otherwise a null pointer
> is dereferenced.
>
> Signed-off-by: Soenke Huster <[email protected]>
> ---
> net/bluetooth/msft.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
> index 484540855863..d2cf92e834f7 100644
> --- a/net/bluetooth/msft.c
> +++ b/net/bluetooth/msft.c
> @@ -705,6 +705,9 @@ static void msft_monitor_device_evt(struct hci_dev *hdev, struct sk_buff *skb)
>
> handle_data = msft_find_handle_data(hdev, ev->monitor_handle, false);
>

scrap this empty line. The check can got right after the assignment.

> + if (!handle_data)
> + return;
> +
> switch (ev->addr_type) {
> case ADDR_LE_DEV_PUBLIC:
> addr_type = BDADDR_LE_PUBLIC;

Regards

Marcel