From: Kees Cook <keescook@chromium.org>
To: "Reshetova, Elena" <elena.reshetova@intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Jann Horn <jannh@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Catalin Marinas <catalin.marinas@arm.com>,
the arch/x86 maintainers <x86@kernel.org>,
kernel list <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Alexander Potapenko <glider@google.com>,
Andy Lutomirski <luto@kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2 0/5] Optionally randomize kernel stack offset each syscall
Date: Wed, 25 Mar 2020 13:27:02 -0700 [thread overview]
Message-ID: <202003251322.180F2536E@keescook> (raw)
In-Reply-To: <BL0PR11MB3281D8D615FA521401B8E320E7CE0@BL0PR11MB3281.namprd11.prod.outlook.com>
On Wed, Mar 25, 2020 at 12:15:12PM +0000, Reshetova, Elena wrote:
> > > Also, are you sure that it isn't possible to make the syscall that
> > > leaked its stack pointer never return to userspace (via ptrace or
> > > SIGSTOP or something like that), and therefore never realign its
> > > stack, while keeping some controlled data present on the syscall's
> > > stack?
>
> How would you reliably detect that a stack pointer has been leaked
> to userspace while it has been in a syscall? Does not seem to be a trivial
> task to me.
Well, my expectation is that folks using this defense are also using
panic_on_warn sysctl, etc, so attackers don't get a chance to actually
_use_ register values spilled to dmesg.
--
Kees Cook
_______________________________________________
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2020-03-25 20:27 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 20:32 [PATCH v2 0/5] Optionally randomize kernel stack offset each syscall Kees Cook
2020-03-24 20:32 ` [PATCH v2 1/5] jump_label: Provide CONFIG-driven build state defaults Kees Cook
2020-03-24 22:06 ` Peter Zijlstra
2020-03-24 20:32 ` [PATCH v2 2/5] init_on_alloc: Unpessimize default-on builds Kees Cook
2020-03-26 15:48 ` Alexander Potapenko
2020-03-24 20:32 ` [PATCH v2 3/5] stack: Optionally randomize kernel stack offset each syscall Kees Cook
2020-03-30 11:25 ` Mark Rutland
2020-03-30 18:18 ` Kees Cook
2020-03-30 18:27 ` Kees Cook
2020-03-24 20:32 ` [PATCH v2 4/5] x86/entry: Enable random_kstack_offset support Kees Cook
2020-03-28 22:26 ` Kees Cook
2020-03-24 20:32 ` [PATCH v2 5/5] arm64: entry: " Kees Cook
2020-03-25 13:21 ` Mark Rutland
2020-03-25 20:22 ` Kees Cook
2020-03-26 11:15 ` Mark Rutland
2020-03-26 16:31 ` Kees Cook
2020-03-30 11:26 ` Mark Rutland
2020-04-20 20:54 ` Will Deacon
2020-04-20 22:34 ` Kees Cook
2020-04-21 7:02 ` Will Deacon
2020-03-24 21:28 ` [PATCH v2 0/5] Optionally randomize kernel stack offset each syscall Jann Horn
2020-03-24 23:07 ` Kees Cook
2020-03-25 12:15 ` Reshetova, Elena
2020-03-25 20:27 ` Kees Cook [this message]
2020-03-25 23:20 ` Jann Horn
2020-03-26 17:18 ` Kees Cook
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