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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Thu, 4 Aug 2022 10:20:34 +0200
Message-ID: <CAK8P3a1ychAteScPbzGymM3UOinxY93rVnGeLsLOggmsRCBB+g@mail.gmail.com>
Subject: Re: [PATCH] char: mwave: fix return type in ioctl
To:     Dan Carpenter <dan.carpenter@oracle.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        kernel-janitors <kernel-janitors@vger.kernel.org>
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On Thu, Aug 4, 2022 at 9:06 AM Dan Carpenter <dan.carpenter@oracle.com> wrote:
>
> This function is supposed to return zero for success or negative error
> code on failure.  Unfortunately the "retval" is declared as unsigned int
> and the function returns type long.  That means that on 64 bit systems
> it will return positive values on error.
>
> Fixes: 909d145f0dec ("mwave: ioctl BKL pushdown")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> The Fixes tag is sort of debatable.  "retval" should have always been
> declared as an int.  But the BKL change is when the return type for
> the ioctl changed from int to long, so it's when the bug started to
> affect user space.

Nice catch, I wonder how many other drivers I broke in that series.
Have you gone through my BKL commits from that time period
to see if any others are affected?

Acked-by: Arnd Bergmann <arnd@arndb.de>