59 lines
1.9 KiB
Diff
59 lines
1.9 KiB
Diff
From: Marc Zyngier <marc.zyngier@arm.com>
|
|
Date: Thu, 27 Sep 2018 16:53:22 +0100
|
|
Subject: arm64: KVM: Sanitize PSTATE.M when being set from userspace
|
|
Origin: https://git.kernel.org/linus/2a3f93459d689d990b3ecfbe782fec89b97d3279
|
|
Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2018-18021
|
|
|
|
Not all execution modes are valid for a guest, and some of them
|
|
depend on what the HW actually supports. Let's verify that what
|
|
userspace provides is compatible with both the VM settings and
|
|
the HW capabilities.
|
|
|
|
Cc: <stable@vger.kernel.org>
|
|
Fixes: 0d854a60b1d7 ("arm64: KVM: enable initialization of a 32bit vcpu")
|
|
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
|
|
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
|
|
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
|
|
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
|
|
Signed-off-by: Will Deacon <will.deacon@arm.com>
|
|
[carnil: Backport for 4.18: Cherrypick directly commit from 4.18.12 /
|
|
926415e1e4c9]
|
|
---
|
|
arch/arm64/kvm/guest.c | 10 +++++++++-
|
|
1 file changed, 9 insertions(+), 1 deletion(-)
|
|
|
|
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
|
|
index 4a177629862b..d5c6bb1562d8 100644
|
|
--- a/arch/arm64/kvm/guest.c
|
|
+++ b/arch/arm64/kvm/guest.c
|
|
@@ -152,17 +152,25 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
|
|
}
|
|
|
|
if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
|
|
- u32 mode = (*(u32 *)valp) & COMPAT_PSR_MODE_MASK;
|
|
+ u64 mode = (*(u64 *)valp) & COMPAT_PSR_MODE_MASK;
|
|
switch (mode) {
|
|
case COMPAT_PSR_MODE_USR:
|
|
+ if (!system_supports_32bit_el0())
|
|
+ return -EINVAL;
|
|
+ break;
|
|
case COMPAT_PSR_MODE_FIQ:
|
|
case COMPAT_PSR_MODE_IRQ:
|
|
case COMPAT_PSR_MODE_SVC:
|
|
case COMPAT_PSR_MODE_ABT:
|
|
case COMPAT_PSR_MODE_UND:
|
|
+ if (!vcpu_el1_is_32bit(vcpu))
|
|
+ return -EINVAL;
|
|
+ break;
|
|
case PSR_MODE_EL0t:
|
|
case PSR_MODE_EL1t:
|
|
case PSR_MODE_EL1h:
|
|
+ if (vcpu_el1_is_32bit(vcpu))
|
|
+ return -EINVAL;
|
|
break;
|
|
default:
|
|
err = -EINVAL;
|
|
--
|
|
2.11.0
|
|
|