From: ori@eigenstate.org
To: 9front@9front.org
Cc: 9front@9front.org
Subject: Re: [9front] drawterm: fix suicide caused by off-by-one write and out-of-bound read in libmemdraw/draw.c (patch)
Date: Fri, 05 Feb 2021 13:18:37 -0800 [thread overview]
Message-ID: <7D1FE3106BC07BB1AC2EC2F04FC1D349@eigenstate.org> (raw)
In-Reply-To: <66A85B05FD8A4DCC2FBCCBC6BC5F9FFB@gmail.com>
Quoth boehm.igor@gmail.com:
> for(i=0; i<dx; i++){
> - u = r[0] | (r[1]<<8) | (r[2]<<16) | (r[3]<<24);
> + for(j = 0, u = 0 ; j < 4 && r+j < end ; j++)
> + u |= r[j] << (8*j);
>
This fix seems wrong: 'u = ...' is loading a pixel. Why
would we ever want to load *half* a pixel?
it seems like we either want to stop early, or ensure we
allocate the right size image.
next prev parent reply other threads:[~2021-02-06 2:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-04 21:19 boehm.igor
2021-02-05 21:18 ` ori [this message]
2021-02-06 10:05 ` boehm.igor
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