From: Alexander Potapenko <glider@google.com>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
sunhaoyl@outlook.com
Subject: Re: [PATCH] fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()
Date: Tue, 21 Apr 2020 14:54:23 +0200 [thread overview]
Message-ID: <CAG_fn=X_eQ4G-0+oAO_q+_zRnkfMf4uhfMcnoYt4i1N_noKgdA@mail.gmail.com> (raw)
In-Reply-To: <20200421034249.GB23230@ZenIV.linux.org.uk>
On Tue, Apr 21, 2020 at 5:42 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Mon, Apr 20, 2020 at 03:41:40PM -0700, Kees Cook wrote:
> > On Mon, Apr 20, 2020 at 03:33:52PM -0700, Andrew Morton wrote:
> > > On Sun, 19 Apr 2020 12:08:48 +0200 glider@google.com wrote:
> > >
> > > > KMSAN reported uninitialized data being written to disk when dumping
> > > > core. As a result, several kilobytes of kmalloc memory may be written to
> > > > the core file and then read by a non-privileged user.
> >
> > Ewww. That's been there for 12 years. Did something change in
> > regset_size() or regset->get()? Do you know what leaves the hole?
>
> Not lately and I would also like to hear the details; which regset it is?
> Should be reasonably easy to find - just memset() the damn thing to something
> recognizable, do whatever triggers that KMSAN report and look at that
> resulting coredump.
>
Seems to be REGSET_XSTATE filled by xstateregs_get().
Is there a ptrace interface also using that function?
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
next prev parent reply other threads:[~2020-04-21 12:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 10:08 [PATCH] fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() glider
2020-04-19 10:10 ` Alexander Potapenko
2020-04-20 22:33 ` Andrew Morton
2020-04-20 22:41 ` Kees Cook
2020-04-21 3:42 ` Al Viro
2020-04-21 8:14 ` Alexander Potapenko
2020-05-12 1:09 ` Al Viro
2020-05-12 3:44 ` Al Viro
2020-05-12 8:20 ` Alexander Potapenko
2020-05-13 3:33 ` Al Viro
2020-05-24 23:45 ` Al Viro
2020-05-26 22:38 ` Al Viro
2020-05-27 12:08 ` Alexander Potapenko
2020-05-27 19:04 ` Borislav Petkov
2020-05-27 19:53 ` Al Viro
2020-05-27 20:09 ` Borislav Petkov
2020-04-21 12:54 ` Alexander Potapenko [this message]
2020-04-21 15:09 ` Jann Horn
2020-04-21 16:04 ` Yu-cheng Yu
2020-04-21 16:16 ` Jann Horn
2020-04-21 16:26 ` Yu-cheng Yu
2020-04-21 20:20 ` Kees Cook
2020-04-21 8:06 ` Alexander Potapenko
2020-05-27 21:55 ` Kees Cook
2020-04-21 8:00 ` Alexander Potapenko
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