diff options
Diffstat (limited to 'arm64_kvm_security.patch')
-rw-r--r-- | arm64_kvm_security.patch | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/arm64_kvm_security.patch b/arm64_kvm_security.patch new file mode 100644 index 000000000..71490d969 --- /dev/null +++ b/arm64_kvm_security.patch @@ -0,0 +1,155 @@ +From d26c25a9d19b5976b319af528886f89cf455692d Mon Sep 17 00:00:00 2001 +From: Dave Martin <Dave.Martin@arm.com> +Date: Thu, 27 Sep 2018 16:53:21 +0100 +Subject: arm64: KVM: Tighten guest core register access from userspace + +From: Dave Martin <Dave.Martin@arm.com> + +commit d26c25a9d19b5976b319af528886f89cf455692d upstream. + +We currently allow userspace to access the core register file +in about any possible way, including straddling multiple +registers and doing unaligned accesses. + +This is not the expected use of the ABI, and nobody is actually +using it that way. Let's tighten it by explicitly checking +the size and alignment for each field of the register file. + +Cc: <stable@vger.kernel.org> +Fixes: 2f4a07c5f9fe ("arm64: KVM: guest one-reg interface") +Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> +Reviewed-by: Mark Rutland <mark.rutland@arm.com> +Signed-off-by: Dave Martin <Dave.Martin@arm.com> +[maz: rewrote Dave's initial patch to be more easily backported] +Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> +Signed-off-by: Will Deacon <will.deacon@arm.com> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> + +--- + arch/arm64/kvm/guest.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ + 1 file changed, 45 insertions(+) + +--- a/arch/arm64/kvm/guest.c ++++ b/arch/arm64/kvm/guest.c +@@ -57,6 +57,45 @@ static u64 core_reg_offset_from_id(u64 i + return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE); + } + ++static int validate_core_offset(const struct kvm_one_reg *reg) ++{ ++ u64 off = core_reg_offset_from_id(reg->id); ++ int size; ++ ++ switch (off) { ++ case KVM_REG_ARM_CORE_REG(regs.regs[0]) ... ++ KVM_REG_ARM_CORE_REG(regs.regs[30]): ++ case KVM_REG_ARM_CORE_REG(regs.sp): ++ case KVM_REG_ARM_CORE_REG(regs.pc): ++ case KVM_REG_ARM_CORE_REG(regs.pstate): ++ case KVM_REG_ARM_CORE_REG(sp_el1): ++ case KVM_REG_ARM_CORE_REG(elr_el1): ++ case KVM_REG_ARM_CORE_REG(spsr[0]) ... ++ KVM_REG_ARM_CORE_REG(spsr[KVM_NR_SPSR - 1]): ++ size = sizeof(__u64); ++ break; ++ ++ case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ... ++ KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]): ++ size = sizeof(__uint128_t); ++ break; ++ ++ case KVM_REG_ARM_CORE_REG(fp_regs.fpsr): ++ case KVM_REG_ARM_CORE_REG(fp_regs.fpcr): ++ size = sizeof(__u32); ++ break; ++ ++ default: ++ return -EINVAL; ++ } ++ ++ if (KVM_REG_SIZE(reg->id) == size && ++ IS_ALIGNED(off, size / sizeof(__u32))) ++ return 0; ++ ++ return -EINVAL; ++} ++ + static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) + { + /* +@@ -76,6 +115,9 @@ static int get_core_reg(struct kvm_vcpu + (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) + return -ENOENT; + ++ if (validate_core_offset(reg)) ++ return -EINVAL; ++ + if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id))) + return -EFAULT; + +@@ -98,6 +140,9 @@ static int set_core_reg(struct kvm_vcpu + (off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs) + return -ENOENT; + ++ if (validate_core_offset(reg)) ++ return -EINVAL; ++ + if (KVM_REG_SIZE(reg->id) > sizeof(tmp)) + return -EINVAL; + +From 2a3f93459d689d990b3ecfbe782fec89b97d3279 Mon Sep 17 00:00:00 2001 +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 + +From: Marc Zyngier <marc.zyngier@arm.com> + +commit 2a3f93459d689d990b3ecfbe782fec89b97d3279 upstream. + +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> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> + +--- + arch/arm64/kvm/guest.c | 10 +++++++++- + 1 file changed, 9 insertions(+), 1 deletion(-) + +--- a/arch/arm64/kvm/guest.c ++++ b/arch/arm64/kvm/guest.c +@@ -152,17 +152,25 @@ static int set_core_reg(struct kvm_vcpu + } + + 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; |