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KVM: arm64: Fix bad dereference on MTE-enabled systems

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commit b6bcdc9f6b upstream.

enter_exception64() performs an MTE check, which involves dereferencing
vcpu->kvm. While vcpu has already been fixed up to be a HYP VA pointer,
kvm is still a pointer in the kernel VA space.

This only affects nVHE configurations with MTE enabled, as in other
cases, the pointer is either valid (VHE) or not dereferenced (!MTE).

Fix this by first converting kvm to a HYP VA pointer.

Fixes: ea7fc1bb1c ("KVM: arm64: Introduce MTE VM feature")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
[maz: commit message tidy-up]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221027120945.29679-1-ryan.roberts@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ryan Roberts 2022-10-27 13:09:45 +01:00 committed by Greg Kroah-Hartman
parent bfa9672f8f
commit fec77482d2
1 changed files with 2 additions and 1 deletions
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3
arch/arm64/kvm/hyp/exception.c
View file

@ -13,6 +13,7 @@
#include <hyp/adjust_pc.h>
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_mmu.h>
#if !defined (__KVM_NVHE_HYPERVISOR__) && !defined (__KVM_VHE_HYPERVISOR__)
#error Hypervisor code only!
@ -115,7 +116,7 @@ static void enter_exception64(struct kvm_vcpu *vcpu, unsigned long target_mode,
new |= (old & PSR_C_BIT);
new |= (old & PSR_V_BIT);
if (kvm_has_mte(vcpu->kvm))
if (kvm_has_mte(kern_hyp_va(vcpu->kvm)))
new |= PSR_TCO_BIT;
new |= (old & PSR_DIT_BIT);