From: Tycho Andersen <tycho@tycho.ws>
To: Kees Cook <keescook@chromium.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
bpf@vger.kernel.org, coreteam@netfilter.org,
Daniel Borkmann <daniel@iogearbox.net>,
"David S. Miller" <davem@davemloft.net>,
Florian Westphal <fw@strlen.de>,
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
Martin KaFai Lau <kafai@fb.com>,
LKML <linux-kernel@vger.kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Network Development <netdev@vger.kernel.org>,
netfilter-devel@vger.kernel.org,
Pablo Neira Ayuso <pablo@netfilter.org>,
Song Liu <songliubraving@fb.com>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
Will Drewry <wad@chromium.org>,
wenxu@ucloud.cn, Yonghong Song <yhs@fb.com>,
syzbot <syzbot+b562969adb2e04af3442@syzkaller.appspotmail.com>
Subject: Re: KASAN: use-after-free Read in seccomp_notify_release (2)
Date: Tue, 23 Apr 2019 15:51:27 -0600 [thread overview]
Message-ID: <20190423215127.GJ3758@cisco> (raw)
In-Reply-To: <CAGXu5jLBd-u=ywxiEjmrLMj9TMRVnLOHHKfWKQ_fEosDFjPoog@mail.gmail.com>
On Tue, Apr 23, 2019 at 02:39:52PM -0700, Kees Cook wrote:
> On Mon, Mar 25, 2019 at 1:02 AM syzbot
> <syzbot+b562969adb2e04af3442@syzkaller.appspotmail.com> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 1bdd3dbf Merge tag 'io_uring-20190323' of git://git.kernel..
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=12ae5b93200000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=9a31fb246de2a622
> > dashboard link: https://syzkaller.appspot.com/bug?extid=b562969adb2e04af3442
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=162ca25d200000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1733b53b200000
> >
> > The bug was bisected to:
> >
> > commit a799aea0988ea0d1b1f263e996fdad2f6133c680
> > Author: wenxu <wenxu@ucloud.cn>
> > Date: Wed Jan 9 02:40:11 2019 +0000
> >
> > netfilter: nft_flow_offload: Fix reverse route lookup
>
> This bisection looks bogus?
>
> However, I _can_ trigger the problem on this kernel version with this
> config. (And not with Linus's latest tree.)
>
> The PoC is identical to the prior report[1] that we thought was fixed.
> Perhaps the fix didn't actually fix it? (I mean
> a811dc61559e0c8003f1086c2a4dc8e4d5ae4cb8) But it's been silent for 29
> days now, so I'm not sure what's going on.
>
> Tycho are you able to reproduce this on the older tree?
It looks like this case is using TSYNC and NEW_LISTENER together:
syscall(__NR_seccomp, 1, 0xb, 0x20000140);
and I did fix a uaf with TSYNC and NEW_LISTENER in this series:
https://lore.kernel.org/lkml/20190306201413.14153-2-tycho@tycho.ws/T/#u
which seems like it's probably related. I don't think the above ever
got applied though?
Tycho
next prev parent reply other threads:[~2019-04-23 21:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-25 8:02 KASAN: use-after-free Read in seccomp_notify_release (2) syzbot
2019-04-23 21:39 ` Kees Cook
2019-04-23 21:51 ` Tycho Andersen [this message]
2019-04-23 22:06 ` Kees Cook
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=20190423215127.GJ3758@cisco \
--to=tycho@tycho.ws \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=coreteam@netfilter.org \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=fw@strlen.de \
--cc=kadlec@blackhole.kfki.hu \
--cc=kafai@fb.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=songliubraving@fb.com \
--cc=syzbot+b562969adb2e04af3442@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
--cc=wad@chromium.org \
--cc=wenxu@ucloud.cn \
--cc=yhs@fb.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.