* [PATCH 1/3] arm64: fix possible spectre-v1 in ptrace_hbp_get_event()
2018-04-25 16:13 [PATCH 0/3] arm64/kvm spectre-v1 fixes Mark Rutland
@ 2018-04-25 16:13 ` Mark Rutland
2018-04-25 16:13 ` [PATCH 2/3] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq() Mark Rutland
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Mark Rutland @ 2018-04-25 16:13 UTC (permalink / raw)
To: linux-arm-kernel
It's possible for userspace to control idx. Sanitize idx when using it
as an array index.
Found by smatch.
Signed-off-by: Mark Rutland <mark.rutland@arm•com>
Cc: Catalin Marinas <catalin.marinas@arm•com>
Cc: Will Deacon <will.deacon@arm•com>
---
arch/arm64/kernel/ptrace.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 71d99af24ef2..49830b5586b4 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -25,6 +25,7 @@
#include <linux/sched/signal.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
+#include <linux/nospec.h>
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/user.h>
@@ -249,15 +250,20 @@ static struct perf_event *ptrace_hbp_get_event(unsigned int note_type,
switch (note_type) {
case NT_ARM_HW_BREAK:
- if (idx < ARM_MAX_BRP)
- bp = tsk->thread.debug.hbp_break[idx];
+ if (idx >= ARM_MAX_BRP)
+ goto out;
+ idx = array_index_nospec(idx, ARM_MAX_BRP);
+ bp = tsk->thread.debug.hbp_break[idx];
break;
case NT_ARM_HW_WATCH:
- if (idx < ARM_MAX_WRP)
- bp = tsk->thread.debug.hbp_watch[idx];
+ if (idx >= ARM_MAX_WRP)
+ goto out;
+ idx = array_index_nospec(idx, ARM_MAX_WRP);
+ bp = tsk->thread.debug.hbp_watch[idx];
break;
}
+out:
return bp;
}
--
2.11.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/3] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()
2018-04-25 16:13 [PATCH 0/3] arm64/kvm spectre-v1 fixes Mark Rutland
2018-04-25 16:13 ` [PATCH 1/3] arm64: fix possible spectre-v1 in ptrace_hbp_get_event() Mark Rutland
@ 2018-04-25 16:13 ` Mark Rutland
2018-04-25 16:13 ` [PATCH 3/3] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr() Mark Rutland
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Mark Rutland @ 2018-04-25 16:13 UTC (permalink / raw)
To: linux-arm-kernel
It's possible for userspace to control intid. Sanitize intid when using
it as an array index.
At the same time, sort the includes when adding <linux/nospec.h>.
Found by smatch.
Signed-off-by: Mark Rutland <mark.rutland@arm•com>
Cc: Christoffer Dall <cdall@kernel•org>
Cc: Marc Zyngier <marc.zyngier@arm•com>
Cc: kvmarm at lists.cs.columbia.edu
---
virt/kvm/arm/vgic/vgic.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
index e74baec76361..bd125563b15b 100644
--- a/virt/kvm/arm/vgic/vgic.c
+++ b/virt/kvm/arm/vgic/vgic.c
@@ -14,11 +14,13 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <linux/interrupt.h>
+#include <linux/irq.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
#include <linux/list_sort.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
+#include <linux/nospec.h>
+
#include <asm/kvm_hyp.h>
#include "vgic.h"
@@ -101,12 +103,16 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
u32 intid)
{
/* SGIs and PPIs */
- if (intid <= VGIC_MAX_PRIVATE)
+ if (intid <= VGIC_MAX_PRIVATE) {
+ intid = array_index_nospec(intid, VGIC_MAX_PRIVATE);
return &vcpu->arch.vgic_cpu.private_irqs[intid];
+ }
/* SPIs */
- if (intid <= VGIC_MAX_SPI)
+ if (intid <= VGIC_MAX_SPI) {
+ intid = array_index_nospec(intid, VGIC_MAX_SPI);
return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
+ }
/* LPIs */
if (intid >= VGIC_MIN_LPI)
--
2.11.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 3/3] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr()
2018-04-25 16:13 [PATCH 0/3] arm64/kvm spectre-v1 fixes Mark Rutland
2018-04-25 16:13 ` [PATCH 1/3] arm64: fix possible spectre-v1 in ptrace_hbp_get_event() Mark Rutland
2018-04-25 16:13 ` [PATCH 2/3] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq() Mark Rutland
@ 2018-04-25 16:13 ` Mark Rutland
2018-04-26 10:37 ` [PATCH 0/3] arm64/kvm spectre-v1 fixes Marc Zyngier
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Mark Rutland @ 2018-04-25 16:13 UTC (permalink / raw)
To: linux-arm-kernel
It's possible for userspace to control n. Sanitize n when using it as an
array index.
Note that while it appears that n must be bound to the interval [0,3]
due to the way it is extracted from addr, we cannot guarantee that
compiler transformations (and/or future refactoring) will ensure this is
the case, and given this is a slow path it's better to always perform
the masking.
Found by smatch.
Signed-off-by: Mark Rutland <mark.rutland@arm•com>
Cc: Christoffer Dall <cdall@kernel•org>
Cc: Marc Zyngier <marc.zyngier@arm•com>
Cc: kvmarm at lists.cs.columbia.edu
---
virt/kvm/arm/vgic/vgic-mmio-v2.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
index e21e2f49b005..ffc587bf4742 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
@@ -14,6 +14,8 @@
#include <linux/irqchip/arm-gic.h>
#include <linux/kvm.h>
#include <linux/kvm_host.h>
+#include <linux/nospec.h>
+
#include <kvm/iodev.h>
#include <kvm/arm_vgic.h>
@@ -324,6 +326,9 @@ static unsigned long vgic_mmio_read_apr(struct kvm_vcpu *vcpu,
if (n > vgic_v3_max_apr_idx(vcpu))
return 0;
+
+ n = array_index_nospec(n, 4);
+
/* GICv3 only uses ICH_AP1Rn for memory mapped (GICv2) guests */
return vgicv3->vgic_ap1r[n];
}
--
2.11.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 0/3] arm64/kvm spectre-v1 fixes
2018-04-25 16:13 [PATCH 0/3] arm64/kvm spectre-v1 fixes Mark Rutland
` (2 preceding siblings ...)
2018-04-25 16:13 ` [PATCH 3/3] KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr() Mark Rutland
@ 2018-04-26 10:37 ` Marc Zyngier
2018-04-26 14:10 ` Christoffer Dall
2018-04-26 15:58 ` Will Deacon
5 siblings, 0 replies; 7+ messages in thread
From: Marc Zyngier @ 2018-04-26 10:37 UTC (permalink / raw)
To: linux-arm-kernel
On 25/04/18 17:13, Mark Rutland wrote:
> These patches fix arm64-specific potential spectre-v1 gadgets found by
> smatch when run over v4.17-rc2.
>
> I'm still building up my smatch database, so it's possible that there are
> further gadgets to be found.
>
> For the moment I've ignored issues which appear to be cross-architecture.
>
> Thanks,
> Mark.
>
> Mark Rutland (3):
> arm64: fix possible spectre-v1 in ptrace_hbp_get_event()
> KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()
> KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr()
>
> arch/arm64/kernel/ptrace.c | 14 ++++++++++----
> virt/kvm/arm/vgic/vgic-mmio-v2.c | 5 +++++
> virt/kvm/arm/vgic/vgic.c | 14 ++++++++++----
> 3 files changed, 25 insertions(+), 8 deletions(-)
>
For the KVM patches:
Acked-by: Marc Zyngier <marc.zyngier@arm•com>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH 0/3] arm64/kvm spectre-v1 fixes
2018-04-25 16:13 [PATCH 0/3] arm64/kvm spectre-v1 fixes Mark Rutland
` (3 preceding siblings ...)
2018-04-26 10:37 ` [PATCH 0/3] arm64/kvm spectre-v1 fixes Marc Zyngier
@ 2018-04-26 14:10 ` Christoffer Dall
2018-04-26 15:58 ` Will Deacon
5 siblings, 0 replies; 7+ messages in thread
From: Christoffer Dall @ 2018-04-26 14:10 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Apr 25, 2018 at 05:13:39PM +0100, Mark Rutland wrote:
> These patches fix arm64-specific potential spectre-v1 gadgets found by
> smatch when run over v4.17-rc2.
>
> I'm still building up my smatch database, so it's possible that there are
> further gadgets to be found.
>
> For the moment I've ignored issues which appear to be cross-architecture.
>
> Thanks,
> Mark.
>
> Mark Rutland (3):
> arm64: fix possible spectre-v1 in ptrace_hbp_get_event()
> KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()
> KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr()
For the KVM-related parts:
Acked-by: Christoffer Dall <christoffer.dall@arm•com>
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH 0/3] arm64/kvm spectre-v1 fixes
2018-04-25 16:13 [PATCH 0/3] arm64/kvm spectre-v1 fixes Mark Rutland
` (4 preceding siblings ...)
2018-04-26 14:10 ` Christoffer Dall
@ 2018-04-26 15:58 ` Will Deacon
5 siblings, 0 replies; 7+ messages in thread
From: Will Deacon @ 2018-04-26 15:58 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Apr 25, 2018 at 05:13:39PM +0100, Mark Rutland wrote:
> These patches fix arm64-specific potential spectre-v1 gadgets found by
> smatch when run over v4.17-rc2.
>
> I'm still building up my smatch database, so it's possible that there are
> further gadgets to be found.
>
> For the moment I've ignored issues which appear to be cross-architecture.
>
> Thanks,
> Mark.
>
> Mark Rutland (3):
> arm64: fix possible spectre-v1 in ptrace_hbp_get_event()
> KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_get_irq()
> KVM: arm/arm64: vgic: fix possible spectre-v1 in vgic_mmio_read_apr()
Thanks, I'll pick these up as fixes with Christoffer and Marc's acks on the
kvm parts.
Will
^ permalink raw reply [flat|nested] 7+ messages in thread