From: Alexander Potapenko <glider@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
sunhaoyl@outlook.com, Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH] fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()
Date: Tue, 21 Apr 2020 10:00:58 +0200 [thread overview]
Message-ID: <CAG_fn=VSxh1yXa7yCGHwsxvGT3+DGmJkrqDrMcHGPHBCWRrBMA@mail.gmail.com> (raw)
In-Reply-To: <20200420153352.6682533e794f591dae7aafbc@linux-foundation.org>
On Tue, Apr 21, 2020 at 12:33 AM Andrew Morton
<akpm@linux-foundation.org> 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.
> >
> > ...
> >
> > --- a/fs/binfmt_elf.c
> > +++ b/fs/binfmt_elf.c
> > @@ -1733,7 +1733,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
> > (!regset->active || regset->active(t->task, regset) > 0)) {
> > int ret;
> > size_t size = regset_size(t->task, regset);
> > - void *data = kmalloc(size, GFP_KERNEL);
> > + void *data = kzalloc(size, GFP_KERNEL);
> > if (unlikely(!data))
> > return 0;
> > ret = regset->get(t->task, regset,
>
> This seems to be a quite easy way of exposing quite a large amount of
> kernel memory contents, so I think I'll add a cc:stable to this patch?
Correct. Sorry, I forgot about this.
The reporter is also happy with the Reported-by: tag, so you can
ignore the note.
--
Alexander Potapenko
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prev parent reply other threads:[~2020-04-21 8:01 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
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 [this message]
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