[PATCH] Bluetooth: A2MP: Do not set rsp.id to zero

[PATCH] Bluetooth: A2MP: Do not set rsp.id to zero

[Stefan Gottwald]

Due to security reasons the rsp struct is not zerod out in one case this will
also zero out the former set rsp.id which seems to be wrong.

Signed-off-by: Stefan Gottwald <gotti79@posteo.net>
---
 net/bluetooth/a2mp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
index da7fd7c..7a1e0b7 100644
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -381,10 +381,11 @@ static int a2mp_getampassoc_req(struct amp_mgr *mgr, struct sk_buff *skb,
 	hdev = hci_dev_get(req->id);
 	if (!hdev || hdev->amp_type == AMP_TYPE_BREDR || tmp) {
 		struct a2mp_amp_assoc_rsp rsp;
-		rsp.id = req->id;
 
 		memset(&rsp, 0, sizeof(rsp));
 
+		rsp.id = req->id;
+
 		if (tmp) {
 			rsp.status = A2MP_STATUS_COLLISION_OCCURED;
 			amp_mgr_put(tmp);
-- 
2.7.4

Re: [PATCH] Bluetooth: A2MP: Do not set rsp.id to zero

[Stefan Gottwald]

Am Sonntag, den 18.10.2020, 10:05 +0200 schrieb Stefan Gottwald:
> Due to security reasons the rsp struct is not zerod out in one case this will
> also zero out the former set rsp.id which seems to be wrong.
> 
> Signed-off-by: Stefan Gottwald <gotti79@posteo.net>
> ---
>  net/bluetooth/a2mp.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
> index da7fd7c..7a1e0b7 100644
> --- a/net/bluetooth/a2mp.c
> +++ b/net/bluetooth/a2mp.c
> @@ -381,10 +381,11 @@ static int a2mp_getampassoc_req(struct amp_mgr *mgr, struct sk_buff *skb,
>  	hdev = hci_dev_get(req->id);
>  	if (!hdev || hdev->amp_type == AMP_TYPE_BREDR || tmp) {
>  		struct a2mp_amp_assoc_rsp rsp;
> -		rsp.id = req->id;
>  
>  		memset(&rsp, 0, sizeof(rsp));
>  
> +		rsp.id = req->id;
> +
>  		if (tmp) {
>  			rsp.status = A2MP_STATUS_COLLISION_OCCURED;
>  			amp_mgr_put(tmp);

As it seems I'm too slow there is already a fix from the author of the initial patch.

https://lore.kernel.org/linux-bluetooth/20201016180956.707681-2-luiz.dentz@gmail.com/

There is a additional patch in this series which might also be a important fix

https://lore.kernel.org/linux-bluetooth/20201016180956.707681-1-luiz.dentz@gmail.com/

Thanks to a LWN member pointing this out to me.