From: Greg KH <gregkh@linuxfoundation.org>
To: Hassan Shahbazi <h.shahbazi.git@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drivers: tty: vt: vt.c: fix NULL dereference crash
Date: Fri, 12 Mar 2021 09:33:37 +0100 [thread overview]
Message-ID: <YEsnYVwzRoEsbkie@kroah.com> (raw)
In-Reply-To: <20210307105642.112572-1-h.shahbazi.git@gmail.com>
On Sun, Mar 07, 2021 at 12:56:43PM +0200, Hassan Shahbazi wrote:
> Fix a NULL deference crash on hiding the cursor.
>
> Reported by: syzbot
> https://syzkaller.appspot.com/bug?id=defb47bf56e1c14d5687280c7bb91ce7b608b94b
>
> Signed-off-by: Hassan Shahbazi <h.shahbazi.git@gmail.com>
> ---
> drivers/tty/vt/vt.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
> index 284b07224c55..8c3e83c81341 100644
> --- a/drivers/tty/vt/vt.c
> +++ b/drivers/tty/vt/vt.c
> @@ -904,7 +904,9 @@ static void hide_cursor(struct vc_data *vc)
> if (vc_is_sel(vc))
> clear_selection();
>
> - vc->vc_sw->con_cursor(vc, CM_ERASE);
> + if (vc->vc_sw)
> + vc->vc_sw->con_cursor(vc, CM_ERASE);
> +
> hide_softcursor(vc);
> }
>
> --
> 2.26.2
>
Are you sure this actually fixes the problem? How did you test it? Did
syzbot test this?
I had a few reports of this patch _not_ solving the problem, so getting
confirmation of this would be good.
thanks,
greg k-h
next prev parent reply other threads:[~2021-03-12 8:34 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-07 10:56 [PATCH] drivers: tty: vt: vt.c: fix NULL dereference crash Hassan Shahbazi
2021-03-12 8:33 ` Greg KH [this message]
2021-03-12 9:07 ` Fatih Yildirim
2021-03-12 15:43 ` Du Cheng
2021-03-13 9:12 ` Hassan Shahbazi
2021-03-12 15:05 ` Du Cheng
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