2013-06-21 14:25:11

by Jaganath Kanakkassery

Subject: [PATCH] Bluetooth: Fix invalid length check in l2cap_information_rsp()

The length check is invalid since the length varies with type of
info response.

This was introduced by the commit cb3b3152b2f5939d67005cff841a1ca748b19888

Because of this, l2cap info rsp is not handled and command reject is sent.

> ACL data: handle 11 flags 0x02 dlen 16
L2CAP(s): Info rsp: type 2 result 0
Extended feature mask 0x00b8
Enhanced Retransmission mode
Streaming mode
FCS Option
Fixed Channels
< ACL data: handle 11 flags 0x00 dlen 10
L2CAP(s): Command rej: reason 0
Command not understood

Signed-off-by: Jaganath Kanakkassery <[email protected]>
Signed-off-by: Chan-Yeol Park <[email protected]>
---
net/bluetooth/l2cap_core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 4be6a26..68843a2 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4333,7 +4333,7 @@ static inline int l2cap_information_rsp(struct l2cap_conn *conn,
struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
u16 type, result;

- if (cmd_len != sizeof(*rsp))
+ if (cmd_len < sizeof(*rsp))
return -EPROTO;

type = __le16_to_cpu(rsp->type);
--
1.7.9.5

2013-06-21 15:52:07

by Johan Hedberg

Subject: Re: [PATCH] Bluetooth: Fix invalid length check in l2cap_information_rsp()

Hi Jaganath,

On Fri, Jun 21, 2013, Jaganath Kanakkassery wrote:
> The length check is invalid since the length varies with type of
> info response.
>
> This was introduced by the commit cb3b3152b2f5939d67005cff841a1ca748b19888
>
> Because of this, l2cap info rsp is not handled and command reject is sent.
>
> > ACL data: handle 11 flags 0x02 dlen 16
> L2CAP(s): Info rsp: type 2 result 0
> Extended feature mask 0x00b8
> Enhanced Retransmission mode
> Streaming mode
> FCS Option
> Fixed Channels
> < ACL data: handle 11 flags 0x00 dlen 10
> L2CAP(s): Command rej: reason 0
> Command not understood
>
> Signed-off-by: Jaganath Kanakkassery <[email protected]>
> Signed-off-by: Chan-Yeol Park <[email protected]>
> ---
> net/bluetooth/l2cap_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 4be6a26..68843a2 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -4333,7 +4333,7 @@ static inline int l2cap_information_rsp(struct l2cap_conn *conn,
> struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) data;
> u16 type, result;
>
> - if (cmd_len != sizeof(*rsp))
> + if (cmd_len < sizeof(*rsp))
> return -EPROTO;
>
> type = __le16_to_cpu(rsp->type);

Good catch, and I have no idea how I missed this one in the original
patch. This patch should also get the Cc: stable designator so that it
goes to all places that the original patch went to as well.

Acked-by: Johan Hedberg <[email protected]>

Johan