On Tue, 21 Jan 2020 at 04:30, Michael Ellerman <m...@ellerman.id.au> wrote: > > From: Joel Stanley <j...@jms.id.au> > > This turns on HARDENED_USERCOPY with HARDENED_USERCOPY_PAGESPAN, and > FORTIFY_SOURCE. > > It also enables SECURITY_LOCKDOWN_LSM with _EARLY and > LOCK_DOWN_KERNEL_FORCE_INTEGRITY options enabled. This still allows > xmon to be used in read-only mode. > > MODULE_SIG is selected by lockdown, so it is still enabled. > > Signed-off-by: Joel Stanley <j...@jms.id.au> > [mpe: Switch to lockdown integrity mode per oohal] > Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
I did some testing and with change we break kexec. As it's critical for this kernel to be able to kexec we need to set KEXEC_FILE=y if we're setting FORCE_INTEGRITY=y. I've tested your series with that modification made and userspace was once again able to kexec (with -s). Cheers, Joel > --- > arch/powerpc/configs/skiroot_defconfig | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > v2: Switch to lockdown integrity mode rather than confidentiality as noticed > by > dja and discussed with jms and oohal. > > diff --git a/arch/powerpc/configs/skiroot_defconfig > b/arch/powerpc/configs/skiroot_defconfig > index 24a210fe0049..93b478436a2b 100644 > --- a/arch/powerpc/configs/skiroot_defconfig > +++ b/arch/powerpc/configs/skiroot_defconfig > @@ -49,7 +49,6 @@ CONFIG_JUMP_LABEL=y > CONFIG_STRICT_KERNEL_RWX=y > CONFIG_MODULES=y > CONFIG_MODULE_UNLOAD=y > -CONFIG_MODULE_SIG=y > CONFIG_MODULE_SIG_FORCE=y > CONFIG_MODULE_SIG_SHA512=y > CONFIG_PARTITION_ADVANCED=y > @@ -272,6 +271,16 @@ CONFIG_NLS_ASCII=y > CONFIG_NLS_ISO8859_1=y > CONFIG_NLS_UTF8=y > CONFIG_ENCRYPTED_KEYS=y > +CONFIG_SECURITY=y > +CONFIG_HARDENED_USERCOPY=y > +# CONFIG_HARDENED_USERCOPY_FALLBACK is not set > +CONFIG_HARDENED_USERCOPY_PAGESPAN=y > +CONFIG_FORTIFY_SOURCE=y > +CONFIG_SECURITY_LOCKDOWN_LSM=y > +CONFIG_SECURITY_LOCKDOWN_LSM_EARLY=y > +CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY=y > +# CONFIG_INTEGRITY is not set > +CONFIG_LSM="yama,loadpin,safesetid,integrity" > # CONFIG_CRYPTO_HW is not set > CONFIG_CRC16=y > CONFIG_CRC_ITU_T=y > -- > 2.21.1 >
