From: David Herrmann <dh.herrmann@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: labbott@redhat.com,
"open list:HID CORE LAYER" <linux-input@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Jiri Kosina <jikos@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>,
xiongfeng.wang@linaro.org
Subject: Re: [PATCH] Revert "HID: uhid: use strlcpy() instead of strncpy()"
Date: Thu, 15 Nov 2018 12:55:44 +0100 [thread overview]
Message-ID: <CANq1E4T6rKjVPwGd-4CDWZzFYz1ohzPSpKGd2kK+O4BNSe--Hg@mail.gmail.com> (raw)
In-Reply-To: <CAGXu5jJJGg5_crJ3v+AG5JZWVGLpDvZGr0UVyurzFxcv9Fwa5A@mail.gmail.com>
Hi
On Thu, Nov 15, 2018 at 12:09 AM Kees Cook <keescook@chromium.org> wrote:
> On Wed, Nov 14, 2018 at 9:40 AM, Laura Abbott <labbott@redhat.com> wrote:
[...]
> > Can we switch to strscpy instead? This will quiet gcc and avoid the
> > issues with strlcpy.
>
> Yes please: it looks like these strings are expected to be NUL
> terminated, so strscpy() without the "- 1" and min() logic would be
> the correct solution here.
"the correct solution"? To my knowledge the original code was correct
as well. Am I missing something?
> If @hid is already zero, then this would
> just be:
>
> strscpy(hid->name, ev->u.create2.name, sizeof(hid->name));
> strscpy(hid->phys, ev->u.create2.phys, sizeof(hid->phys));
> strscpy(hid->uniq, ev->u.create2.uniq, sizeof(hid->uniq));
>
> If they are NOT NUL terminated, then keep using strncpy() but mark the
> fields in the struct with the __nonstring attribute.
They are supposed to be NUL terminated, but for compatibility reasons
we allow them to be not. So I don't think your proposal is safe.
Thanks
David
next prev parent reply other threads:[~2018-11-15 11:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-14 13:16 [PATCH] Revert "HID: uhid: use strlcpy() instead of strncpy()" David Herrmann
2018-11-14 15:40 ` Laura Abbott
2018-11-14 23:09 ` Kees Cook
2018-11-15 11:55 ` David Herrmann [this message]
2018-11-16 1:10 ` Kees Cook
2018-11-19 13:33 ` Jiri Kosina
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