Re: [Bluez PATCH v2] bluetooth: fix passkey uninitialized when used

[Nick Desaulniers]

On Tue, Feb 18, 2020 at 10:45 PM 'Howard Chung' via Clang Built Linux
<clang-built-linux@xxxxxxxxxxxxxxxx> wrote:
>
> This issue cause a warning here
> https://groups.google.com/forum/#!topic/clang-built-linux/kyRKCjRsGoU
>
> Signed-off-by: Howard Chung <howardchung@xxxxxxxxxx>

It can be helpful to just include the text from the warning in the
commit message, for future patches, then a "Link" tag (below) to the
report.  Also,if you use Marcel's suggestions, it's polite to add a
`Suggested-by` tag.

Link: https://groups.google.com/forum/#!topic/clang-built-linux/kyRKCjRsGoU
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Acked-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

>
> ---
>
> Changes in v2:
> - refactor code
>
>  net/bluetooth/smp.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
> index 50e0ac692ec4..929e0bebaf80 100644
> --- a/net/bluetooth/smp.c
> +++ b/net/bluetooth/smp.c
> @@ -2115,7 +2115,7 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
>         struct l2cap_chan *chan = conn->smp;
>         struct smp_chan *smp = chan->data;
>         struct hci_conn *hcon = conn->hcon;
> -       u8 *pkax, *pkbx, *na, *nb;
> +       u8 *pkax, *pkbx, *na, *nb, confirm_hint;
>         u32 passkey;
>         int err;
>
> @@ -2179,13 +2179,12 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
>                  */
>                 if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type,
>                                  hcon->role)) {
> -                       err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst,
> -                                                       hcon->type,
> -                                                       hcon->dst_type,
> -                                                       passkey, 1);
> -                       if (err)
> -                               return SMP_UNSPECIFIED;
> -                       set_bit(SMP_FLAG_WAIT_USER, &smp->flags);
> +                       /* Set passkey to 0. The value can be any number since
> +                        * it'll be ignored anyway.
> +                        */
> +                       passkey = 0;
> +                       confirm_hint = 1;
> +                       goto confirm;
>                 }
>         }
>
> @@ -2206,9 +2205,11 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
>         err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey);
>         if (err)
>                 return SMP_UNSPECIFIED;
> +       confirm_hint = 0;
>
> +confirm:
>         err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type,
> -                                       hcon->dst_type, passkey, 0);
> +                                       hcon->dst_type, passkey, confirm_hint);
>         if (err)
>                 return SMP_UNSPECIFIED;
>
> --

-- 
Thanks,
~Nick Desaulniers