From: Andy Lutomirski <luto@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: "Ingo Molnar" <mingo@kernel.org>,
"Robert Święcki" <robert@swiecki.net>,
"Andy Lutomirski" <luto@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] lib/syscall: Clear return values when no stack
Date: Thu, 23 Mar 2017 16:03:42 -0700 [thread overview]
Message-ID: <CALCETrUvGao=VbUXP9iZuTL9ExAJiU0e8SjMTQTS3x-OYNBcSw@mail.gmail.com> (raw)
In-Reply-To: <20170323224616.GA92694@beast>
On Thu, Mar 23, 2017 at 3:46 PM, Kees Cook <keescook@chromium.org> wrote:
> Commit aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()")
> added logic to handle a process stack not existing, but left sp and pc
> uninitialized, which can be later reported via /proc/$pid/syscall for zombie
> processes, potentially exposing kernel memory to userspace.
>
> Zombie /proc/$pid/syscall before:
> -1 0xffffffff9a060100 0xffff92f42d6ad900
>
> Zombie /proc/$pid/syscall after:
> -1 0x0 0x0
>
> Reported-by: Robert Święcki <robert@swiecki.net>
> Fixes: aa1f1a639621 ("lib/syscall: Pin the task stack in collect_syscall()")
> Cc: stable@vger.kernel.org # v4.9+
> Signed-off-by: Kees Cook <keescook@chromium.org>
Whoops!
Reviewed-by: Andy Lutomirski <luto@kernel.org>
next prev parent reply other threads:[~2017-03-23 23:04 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-23 22:46 [PATCH] lib/syscall: Clear return values when no stack Kees Cook
2017-03-23 23:03 ` Andy Lutomirski [this message]
2017-03-24 6:45 ` [tip:core/urgent] " tip-bot for Kees Cook
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