linux-kernel - [PATCH 4.15 016/202] [Variant 3/Meltdown] arm64: mm: Temporarily disable ARM64_SW_TTBR0

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180215151713.700527466@linuxfoundation.org>
Date:   Thu, 15 Feb 2018 16:15:16 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Mark Rutland <mark.rutland@....com>,
        Laura Abbott <labbott@...hat.com>,
        Shanker Donthineni <shankerd@...eaurora.org>,
        Will Deacon <will.deacon@....com>
Subject: [PATCH 4.15 016/202] [Variant 3/Meltdown] arm64: mm: Temporarily disable ARM64_SW_TTBR0_PAN

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Will Deacon <will.deacon@....com>


Commit 376133b7edc2 upstream.

We're about to rework the way ASIDs are allocated, switch_mm is
implemented and low-level kernel entry/exit is handled, so keep the
ARM64_SW_TTBR0_PAN code out of the way whilst we do the heavy lifting.

It will be re-enabled in a subsequent patch.

Reviewed-by: Mark Rutland <mark.rutland@....com>
Tested-by: Laura Abbott <labbott@...hat.com>
Tested-by: Shanker Donthineni <shankerd@...eaurora.org>
Signed-off-by: Will Deacon <will.deacon@....com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/arm64/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -920,6 +920,7 @@ endif
 
 config ARM64_SW_TTBR0_PAN
 	bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
+	depends on BROKEN       # Temporary while switch_mm is reworked
 	help
 	  Enabling this option prevents the kernel from accessing
 	  user-space memory directly by pointing TTBR0_EL1 to a reserved