From: Albin Babu Varghese <albinbabuvarghese20@gmail.com>
To: Helge Deller <deller@gmx.de>
Cc: Simona Vetter <simona@ffwll.ch>,
syzbot+48b0652a95834717f190@syzkaller.appspotmail.com,
linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds
Date: Wed, 1 Oct 2025 13:19:01 -0400 [thread overview]
Message-ID: <aN1ihRfB-GHTEt_4@arch-box> (raw)
In-Reply-To: <cb00a5e2-6e50-4b01-bcd7-33eeae57ed63@gmx.de>
Hi Helge, Thanks for the review.
> I wonder if the image.height value should be capped in this case,
> instead of not rendering any chars at all?
> Something like (untested!):
>
> + if (image.dy >= info->var.yres)
> + return;
> + image.height = min(image.height, info->var.yres - image.dy);
This looks like a better implementation than what I had. I thought it might be
better to skip the entire row instead of rendering partially. I’m still new to
this subsystem, so thanks for pointing this out. I’ll test the suggested
changes and send a v2.
next prev parent reply other threads:[~2025-10-01 17:19 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-27 7:50 [PATCH] fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds Albin Babu Varghese
2025-09-30 20:46 ` Helge Deller
2025-10-01 17:19 ` Albin Babu Varghese [this message]
2025-10-01 18:36 ` Helge Deller
2025-10-02 8:52 ` Albin Babu Varghese
2025-10-02 10:11 ` Helge Deller
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