From: Mark Rutland <mark.rutland@arm.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: keescook@chromium.org, marc.zyngier@arm.com,
catalin.marinas@arm.com, kernel-hardening@lists.openwall.com,
will.deacon@arm.com, andre.przywara@arm.com, nd@arm.com,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org, labbott@fedoraproject.org
Subject: Re: [PATCH v2 4/5] arm64: mmu: map .text as read-only from the outset
Date: Tue, 14 Feb 2017 17:54:05 +0000 [thread overview]
Message-ID: <20170214175405.GL23718@leverpostej> (raw)
In-Reply-To: <42A48E4E-EF3C-4F28-A660-AFEBB238B698@linaro.org>
On Tue, Feb 14, 2017 at 05:49:19PM +0000, Ard Biesheuvel wrote:
>
> > On 14 Feb 2017, at 17:40, Mark Rutland <mark.rutland@arm.com> wrote:
> >
> >> On Tue, Feb 14, 2017 at 04:15:11PM +0000, Ard Biesheuvel wrote:
> >> Having trivial 'off' switches for security features makes me feel
> >> uneasy (although this is orthogonal to this patch)
> >
> > From my PoV, external debuggers are the sole reason to allow rodata=off
> > for arm64, and we already allow rodata=off.
> >
> >
>
> Indeed. If that is how it works currently, we shouldn't interfere with
> it. If we ever get anywhere with the lockdown patches, we should
> blacklist this parameter (or rather, not whitelist it, since
> blacklisting kernel params to enforce security is infeasible imo)
Agreed on all counts!
Mark.
WARNING: multiple messages have this Message-ID (diff)
From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 4/5] arm64: mmu: map .text as read-only from the outset
Date: Tue, 14 Feb 2017 17:54:05 +0000 [thread overview]
Message-ID: <20170214175405.GL23718@leverpostej> (raw)
In-Reply-To: <42A48E4E-EF3C-4F28-A660-AFEBB238B698@linaro.org>
On Tue, Feb 14, 2017 at 05:49:19PM +0000, Ard Biesheuvel wrote:
>
> > On 14 Feb 2017, at 17:40, Mark Rutland <mark.rutland@arm.com> wrote:
> >
> >> On Tue, Feb 14, 2017 at 04:15:11PM +0000, Ard Biesheuvel wrote:
> >> Having trivial 'off' switches for security features makes me feel
> >> uneasy (although this is orthogonal to this patch)
> >
> > From my PoV, external debuggers are the sole reason to allow rodata=off
> > for arm64, and we already allow rodata=off.
> >
> >
>
> Indeed. If that is how it works currently, we shouldn't interfere with
> it. If we ever get anywhere with the lockdown patches, we should
> blacklist this parameter (or rather, not whitelist it, since
> blacklisting kernel params to enforce security is infeasible imo)
Agreed on all counts!
Mark.
WARNING: multiple messages have this Message-ID (diff)
From: Mark Rutland <mark.rutland@arm.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com,
will.deacon@arm.com, labbott@fedoraproject.org,
kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com,
andre.przywara@arm.com, Suzuki.Poulose@arm.com,
james.morse@arm.com, keescook@chromium.org,
kernel-hardening@lists.openwall.com, nd@arm.com
Subject: [kernel-hardening] Re: [PATCH v2 4/5] arm64: mmu: map .text as read-only from the outset
Date: Tue, 14 Feb 2017 17:54:05 +0000 [thread overview]
Message-ID: <20170214175405.GL23718@leverpostej> (raw)
In-Reply-To: <42A48E4E-EF3C-4F28-A660-AFEBB238B698@linaro.org>
On Tue, Feb 14, 2017 at 05:49:19PM +0000, Ard Biesheuvel wrote:
>
> > On 14 Feb 2017, at 17:40, Mark Rutland <mark.rutland@arm.com> wrote:
> >
> >> On Tue, Feb 14, 2017 at 04:15:11PM +0000, Ard Biesheuvel wrote:
> >> Having trivial 'off' switches for security features makes me feel
> >> uneasy (although this is orthogonal to this patch)
> >
> > From my PoV, external debuggers are the sole reason to allow rodata=off
> > for arm64, and we already allow rodata=off.
> >
> >
>
> Indeed. If that is how it works currently, we shouldn't interfere with
> it. If we ever get anywhere with the lockdown patches, we should
> blacklist this parameter (or rather, not whitelist it, since
> blacklisting kernel params to enforce security is infeasible imo)
Agreed on all counts!
Mark.
next prev parent reply other threads:[~2017-02-14 17:53 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-11 20:23 [PATCH v2 0/5] arm64: mmu: avoid writeable-executable mappings Ard Biesheuvel
2017-02-11 20:23 ` [kernel-hardening] " Ard Biesheuvel
2017-02-11 20:23 ` Ard Biesheuvel
2017-02-11 20:23 ` [PATCH v2 1/5] arm: kvm: move kvm_vgic_global_state out of .text section Ard Biesheuvel
2017-02-11 20:23 ` [kernel-hardening] " Ard Biesheuvel
2017-02-11 20:23 ` Ard Biesheuvel
2017-02-13 17:58 ` Mark Rutland
2017-02-13 17:58 ` [kernel-hardening] " Mark Rutland
2017-02-11 20:23 ` [PATCH v2 2/5] arm64: mmu: move TLB maintenance from callers to create_mapping_late() Ard Biesheuvel
2017-02-11 20:23 ` [kernel-hardening] " Ard Biesheuvel
2017-02-11 20:23 ` Ard Biesheuvel
2017-02-14 15:54 ` Mark Rutland
2017-02-14 15:54 ` [kernel-hardening] " Mark Rutland
2017-02-14 15:54 ` Mark Rutland
2017-02-11 20:23 ` [PATCH v2 3/5] arm64: alternatives: apply boot time fixups via the linear mapping Ard Biesheuvel
2017-02-11 20:23 ` [kernel-hardening] " Ard Biesheuvel
2017-02-11 20:23 ` Ard Biesheuvel
2017-02-14 15:56 ` Mark Rutland
2017-02-14 15:56 ` [kernel-hardening] " Mark Rutland
2017-02-14 15:56 ` Mark Rutland
2017-02-11 20:23 ` [PATCH v2 4/5] arm64: mmu: map .text as read-only from the outset Ard Biesheuvel
2017-02-11 20:23 ` [kernel-hardening] " Ard Biesheuvel
2017-02-11 20:23 ` Ard Biesheuvel
2017-02-14 15:57 ` Mark Rutland
2017-02-14 15:57 ` [kernel-hardening] " Mark Rutland
2017-02-14 15:57 ` Mark Rutland
2017-02-14 16:15 ` Ard Biesheuvel
2017-02-14 16:15 ` [kernel-hardening] " Ard Biesheuvel
2017-02-14 16:15 ` Ard Biesheuvel
2017-02-14 17:40 ` Mark Rutland
2017-02-14 17:40 ` [kernel-hardening] " Mark Rutland
2017-02-14 17:40 ` Mark Rutland
2017-02-14 17:49 ` Ard Biesheuvel
2017-02-14 17:49 ` [kernel-hardening] " Ard Biesheuvel
2017-02-14 17:49 ` Ard Biesheuvel
2017-02-14 17:54 ` Mark Rutland [this message]
2017-02-14 17:54 ` [kernel-hardening] " Mark Rutland
2017-02-14 17:54 ` Mark Rutland
2017-02-11 20:23 ` [PATCH v2 5/5] arm64: mmu: apply strict permissions to .init.text and .init.data Ard Biesheuvel
2017-02-11 20:23 ` [kernel-hardening] " Ard Biesheuvel
2017-02-11 20:23 ` Ard Biesheuvel
2017-02-14 15:57 ` Mark Rutland
2017-02-14 15:57 ` [kernel-hardening] " Mark Rutland
2017-02-14 15:57 ` Mark Rutland
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