Re: [PATCH] ssb-main: Fix division by zero in ssb_calc_clock_rate()

From: Ранд Дееб
Date: Thu Aug 31 2023 - 10:25:27 EST


Dear Krzysztof,

Thank you for your response, now I see, but we already used the standard
tool git send-email to send the patch. It seems we have to set the
transfer-encoding manually (not default), we will fix it next time.
It's our first time trying to send a patch.

Best Regards,
Rand

----- Original Message -----
From: "Krzysztof Kozlowski" <krzk@xxxxxxxxxx>
To: "Rand Deeb" <deeb.rand@xxxxxxxxxxxx>, "Michael Buesch" <m@xxxxxxx>, "linux-wireless" <linux-wireless@xxxxxxxxxxxxxxx>, "linux-kernel" <linux-kernel@xxxxxxxxxxxxxxx>
Cc: "lvc-project" <lvc-project@xxxxxxxxxxxxxxxx>, "Воскресенский Станислав Игоревич" <voskresenski.stanislav@xxxxxxxxxxxx>
Sent: Thursday, August 31, 2023 4:45:15 PM
Subject: Re: [PATCH] ssb-main: Fix division by zero in ssb_calc_clock_rate()

On 30/08/2023 10:27, Rand Deeb wrote:
> In ssb_calc_clock_rate(), the value of m1 may be zero because it is
> initialized using clkfactor_f6_resolv(). This function could return
> zero, so there is a possibility of dividing by zero, we fixed it by
> checking the values before dividing.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.

Version your patches and provide changelog after --- .

>
> Signed-off-by: Rand Deeb <deeb.rand@xxxxxxxxxxxx>
> ---
> drivers/ssb/main.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
> index 0a26984acb2c..e0776a16d04d 100644
> --- a/drivers/ssb/main.c
> +++ b/drivers/ssb/main.c
> @@ -903,13 +903,21 @@ u32 ssb_calc_clock_rate(u32 plltype, u32 n, u32 m)
> case SSB_CHIPCO_CLK_MC_BYPASS:
> return clock;
> case SSB_CHIPCO_CLK_MC_M1:
> - return (clock / m1);
> + if (m1 !=3D 0)

Nothing improved here.

Don't send patches as quoted-printable via some weird mailers.
Recommendation is to use standard tool - git send-email.

As you can easily see on the web - it is re-formatted for quoted-printable:

https://lore.kernel.org/all/20230830082759.23336-1-deeb.rand@xxxxxxxxxxxx/raw

Best regards,
Krzysztof