2021-12-08 07:20:45

by Jεan Sacren

Subject: [PATCH net-next] net: bluetooth: clean up harmless false expression

From: Jean Sacren <[email protected]>

scid is u16 with a range from 0x0000 to 0xffff. L2CAP_CID_DYN_END is
0xffff. We should drop the false check of (scid > L2CAP_CID_DYN_END).

Signed-off-by: Jean Sacren <[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 4f8f37599962..fe5f455646f6 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4118,7 +4118,7 @@ static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
result = L2CAP_CR_NO_MEM;

/* Check for valid dynamic CID range (as per Erratum 3253) */
- if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
+ if (scid < L2CAP_CID_DYN_START) {
result = L2CAP_CR_INVALID_SCID;
goto response;
}

2021-12-08 14:39:09

by Marcel Holtmann

Subject: Re: [PATCH net-next] net: bluetooth: clean up harmless false expression

Hi Jean,

> scid is u16 with a range from 0x0000 to 0xffff. L2CAP_CID_DYN_END is
> 0xffff. We should drop the false check of (scid > L2CAP_CID_DYN_END).
>
> Signed-off-by: Jean Sacren <[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 4f8f37599962..fe5f455646f6 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -4118,7 +4118,7 @@ static struct l2cap_chan *l2cap_connect(struct l2cap_conn *conn,
> result = L2CAP_CR_NO_MEM;
>
> /* Check for valid dynamic CID range (as per Erratum 3253) */
> - if (scid < L2CAP_CID_DYN_START || scid > L2CAP_CID_DYN_END) {
> + if (scid < L2CAP_CID_DYN_START) {
> result = L2CAP_CR_INVALID_SCID;
> goto response;
> }

so I realize that this might be a pointless check, but I rather keep it. It
really doesn’t do any harm.

Regards

Marcel