From: Dan Carpenter <dan.carpenter@oracle.com>
To: Hillf Danton <hdanton@sina.com>
Cc: robdclark@chromium.org, daniel@ffwll.ch, davem@davemloft.net,
airlied@linux.ie, netdev@vger.kernel.org,
syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org, chris@chris-wilson.co.uk,
linaro-mm-sig@lists.linaro.org, eric@anholt.net,
seanpaul@chromium.org, dri-devel@lists.freedesktop.org,
syzbot <syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com>,
alexander.deucher@amd.com, linux-media@vger.kernel.org,
sumit.semwal@linaro.org, christian.koenig@amd.com,
emil.velikov@collabora.com
Subject: Re: KASAN: use-after-free Read in vgem_gem_dumb_create
Date: Sat, 1 Feb 2020 19:25:37 +0300 [thread overview]
Message-ID: <20200201162537.GK1778@kadam> (raw)
In-Reply-To: <20200201090247.10928-1-hdanton@sina.com>
On Sat, Feb 01, 2020 at 05:02:47PM +0800, Hillf Danton wrote:
>
> On Sat, 1 Feb 2020 09:17:57 +0300 Dan Carpenter wrote:
> > On Sat, Feb 01, 2020 at 12:32:09PM +0800, Hillf Danton wrote:
> > >
> > > Release obj in error path.
> > >
> > > --- a/drivers/gpu/drm/vgem/vgem_drv.c
> > > +++ b/drivers/gpu/drm/vgem/vgem_drv.c
> > > @@ -196,10 +196,10 @@ static struct drm_gem_object *vgem_gem_c
> > > return ERR_CAST(obj);
> > >
> > > ret = drm_gem_handle_create(file, &obj->base, handle);
> > > - drm_gem_object_put_unlocked(&obj->base);
> > > - if (ret)
> > > + if (ret) {
> > > + drm_gem_object_put_unlocked(&obj->base);
> > > return ERR_PTR(ret);
> > > -
> > > + }
> > > return &obj->base;
> >
> > Oh yeah. It's weird that we never noticed the success path was broken.
> > It's been that way for three years and no one noticed at all. Very
> > strange.
> >
> > Anyway, it already gets freed on error in drm_gem_handle_create() so
> > we should just delete the drm_gem_object_put_unlocked() here it looks
> > like.
>
> Good catch, Dan :P
> Would you please post a patch sometime convenient next week?
Sure. Will do.
regards,
dan carpenter
_______________________________________________
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
next prev parent reply other threads:[~2020-02-01 16:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-01 4:32 KASAN: use-after-free Read in vgem_gem_dumb_create Hillf Danton
2020-02-01 6:17 ` Dan Carpenter
2020-02-01 9:02 ` Hillf Danton
2020-02-01 16:25 ` Dan Carpenter [this message]
2020-02-02 13:17 ` Daniel Vetter
-- strict thread matches above, loose matches on Subject: below --
2020-01-31 22:28 syzbot
2020-02-01 5:56 ` Dan Carpenter
2020-02-02 4:38 ` syzbot
2020-02-02 13:19 ` Daniel Vetter
2020-02-03 9:06 ` Dan Carpenter
2020-02-03 15:08 ` Christian König
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200201162537.GK1778@kadam \
--to=dan.carpenter@oracle.com \
--cc=airlied@linux.ie \
--cc=alexander.deucher@amd.com \
--cc=amd-gfx@lists.freedesktop.org \
--cc=chris@chris-wilson.co.uk \
--cc=christian.koenig@amd.com \
--cc=daniel@ffwll.ch \
--cc=davem@davemloft.net \
--cc=dri-devel@lists.freedesktop.org \
--cc=emil.velikov@collabora.com \
--cc=eric@anholt.net \
--cc=hdanton@sina.com \
--cc=linaro-mm-sig@lists.linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=robdclark@chromium.org \
--cc=seanpaul@chromium.org \
--cc=sumit.semwal@linaro.org \
--cc=syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox