2017-11-29 05:32:37

by Joonsoo Kim

[permalink] [raw]
Subject: Re: [PATCH 02/18] vchecker: introduce the valid access checker

On Tue, Nov 28, 2017 at 11:41:08AM -0800, Andi Kleen wrote:
> [email protected] writes:
>
> > From: Joonsoo Kim <[email protected]>
>
> Looks useful. Essentially unlimited hardware break points, combined
> with slab.

Thanks!!!

>
> Didn't do a full review, but noticed some things below.
> > +
> > + buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
> > + if (!buf)
> > + return -ENOMEM;
> > +
> > + if (copy_from_user(buf, ubuf, cnt)) {
> > + kfree(buf);
> > + return -EFAULT;
> > + }
> > +
> > + if (isspace(buf[0]))
> > + remove = true;
>
> and that may be uninitialized.

I will add 'cnt == 0' check above.

> and the space changes the operation? That's a strange syntax.

Intention is to clear the all the previous configuration when user
input is '\n'. Will fix it by checking '\n' directly.

>
> > + buf[cnt - 1] = '\0';
>
> That's an underflow of one byte if cnt is 0.

Will add 'cnt == 0' check above.

String parsing part in this patchset will not work properly when the
last input character is not '\n'. I will fix it on the next spin.

Thanks.

From 1585340108321577919@xxx Tue Nov 28 19:42:24 +0000 2017
X-GM-THRID: 1585295599512205164
X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread