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From: Russell Currey <ruscur@russell.cc>
To: linuxppc-dev@lists.ozlabs.org
Cc: Russell Currey <ruscur@russell.cc>,
	christophe.leroy@c-s.fr, joel@jms.id.au, mpe@ellerman.id.au,
	ajd@linux.ibm.com, dja@axtens.net, npiggin@gmail.com,
	kernel-hardening@lists.openwall.com
Subject: [PATCH v6 4/5] powerpc: Set ARCH_HAS_STRICT_MODULE_RWX
Date: Tue, 24 Dec 2019 16:55:44 +1100
Message-ID: <20191224055545.178462-5-ruscur@russell.cc> (raw)
In-Reply-To: <20191224055545.178462-1-ruscur@russell.cc>

To enable strict module RWX on powerpc, set:

    CONFIG_STRICT_MODULE_RWX=y

You should also have CONFIG_STRICT_KERNEL_RWX=y set to have any real
security benefit.

ARCH_HAS_STRICT_MODULE_RWX is set to require ARCH_HAS_STRICT_KERNEL_RWX.
This is due to a quirk in arch/Kconfig and arch/powerpc/Kconfig that
makes STRICT_MODULE_RWX *on by default* in configurations where
STRICT_KERNEL_RWX is *unavailable*.

Since this doesn't make much sense, and module RWX without kernel RWX
doesn't make much sense, having the same dependencies as kernel RWX
works around this problem.

Signed-off-by: Russell Currey <ruscur@russell.cc>
---
 arch/powerpc/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index f0b9b47b5353..97ea012fdff9 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -135,6 +135,7 @@ config PPC
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX	if ((PPC_BOOK3S_64 || PPC32) && !RELOCATABLE && !HIBERNATION)
+	select ARCH_HAS_STRICT_MODULE_RWX	if ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UACCESS_FLUSHCACHE
 	select ARCH_HAS_UACCESS_MCSAFE		if PPC64
-- 
2.24.1


  parent reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-24  5:55 [PATCH v6 0/5] Implement STRICT_MODULE_RWX for powerpc Russell Currey
2019-12-24  5:55 ` [PATCH v6 1/5] powerpc/mm: Implement set_memory() routines Russell Currey
2020-01-08 12:52   ` Christophe Leroy
2020-02-03  0:46     ` Russell Currey
2020-02-03  7:06       ` Christophe Leroy
2020-01-20  8:35   ` Christophe Leroy
2019-12-24  5:55 ` [PATCH v6 2/5] powerpc/kprobes: Mark newly allocated probes as RO Russell Currey
2020-01-08 16:48   ` Christophe Leroy
2019-12-24  5:55 ` [PATCH v6 3/5] powerpc/mm/ptdump: debugfs handler for W+X checks at runtime Russell Currey
2019-12-31 17:14   ` Christophe Leroy
2020-01-07 10:48     ` Michael Ellerman
2019-12-24  5:55 ` Russell Currey [this message]
2019-12-24  5:55 ` [PATCH v6 5/5] powerpc/configs: Enable STRICT_MODULE_RWX in skiroot_defconfig Russell Currey

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