From: Dan Carpenter <dan.carpenter@oracle.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: syzbot <syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com>,
"Dave Airlie" <airlied@linux.ie>,
"Alex Deucher" <alexander.deucher@amd.com>,
"amd-gfx list" <amd-gfx@lists.freedesktop.org>,
"Wilson, Chris" <chris@chris-wilson.co.uk>,
"Christian König" <christian.koenig@amd.com>,
"David Miller" <davem@davemloft.net>,
dri-devel <dri-devel@lists.freedesktop.org>,
"Emil Velikov" <emil.velikov@collabora.com>,
"Anholt, Eric" <eric@anholt.net>,
"moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>,
"Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>, netdev <netdev@vger.kernel.org>,
"Rob Clark" <robdclark@chromium.org>,
"Sean Paul" <seanpaul@chromium.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Subject: Re: KASAN: use-after-free Read in vgem_gem_dumb_create
Date: Mon, 3 Feb 2020 12:06:19 +0300 [thread overview]
Message-ID: <20200203090619.GL1778@kadam> (raw)
In-Reply-To: <CAKMK7uGivsYzP6h9rg0eN34YuOVbee6gnhdOxiys=M=4phK+kw@mail.gmail.com>
On Sun, Feb 02, 2020 at 02:19:18PM +0100, Daniel Vetter wrote:
> On Fri, Jan 31, 2020 at 11:28 PM syzbot
> <syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 39bed42d Merge tag 'for-linus-hmm' of git://git.kernel.org..
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=179465bee00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=2646535f8818ae25
> > dashboard link: https://syzkaller.appspot.com/bug?extid=0dc4444774d419e916c8
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16251279e00000
> >
> > The bug was bisected to:
> >
> > commit 7611750784664db46d0db95631e322aeb263dde7
> > Author: Alex Deucher <alexander.deucher@amd.com>
> > Date: Wed Jun 21 16:31:41 2017 +0000
> >
> > drm/amdgpu: use kernel is_power_of_2 rather than local version
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11628df1e00000
> > final crash: https://syzkaller.appspot.com/x/report.txt?x=13628df1e00000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15628df1e00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+0dc4444774d419e916c8@syzkaller.appspotmail.com
> > Fixes: 761175078466 ("drm/amdgpu: use kernel is_power_of_2 rather than local version")
>
> Aside: This bisect line is complete nonsense ... I'm kinda at the
> point where I'm assuming that syzbot bisect results are garbage, which
> is maybe not what we want. I guess much stricter filtering for noise
> is needed, dunno.
> -Danile
With race conditions the git bisect is often nonsense.
regards,
dan carpenter
next prev parent reply other threads:[~2020-02-03 9:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-31 22:28 KASAN: use-after-free Read in vgem_gem_dumb_create 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 [this message]
2020-02-03 15:08 ` Christian König
[not found] <20200201043209.13412-1-hdanton@sina.com>
2020-02-01 6:17 ` Dan Carpenter
[not found] ` <20200201090247.10928-1-hdanton@sina.com>
2020-02-01 16:25 ` Dan Carpenter
2020-02-02 13:17 ` Daniel Vetter
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