averello/linux-stable-mirror
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2026-09-22 09:34:56 +02:00
Code Issues Packages Projects Releases Wiki Activity

KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU

Browse Source 
commit 8cc8bbbfab upstream.

flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU
on every run. The vGIC list register save and restore use used_lrs as
their loop bound and expect it to stay within the number of implemented
list registers. While this is generally the case, flush_hyp_vcpu()
copies vgic_v3 verbatim and does not enforce this, so a value provided
by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2
(host -> EL2).

Fix by clamping used_lrs to the number of implemented list registers
after the copy, as the trusted path already does in
vgic_flush_lr_state(). The number of implemented list registers is
constant after init, so it is replicated once from
kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on
every entry.

Cc: stable@vger.kernel.org
Fixes: be66e67f17 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260606175614.83273-3-imv4bel@gmail.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
[ tabba: adjust context in flush_hyp_vcpu() and kvm_hyp.h ]
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Hyunwoo Kim
2026-07-24 16:02:56 +02:00
committed by Greg Kroah-Hartman
parent 7b91e51d0e
commit 2c5e72b9fb
3 changed files with 12 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
arch/arm64/include/asm/kvm_hyp.h
+1
View File
@@ -146,5 +146,6 @@ extern u64 kvm_nvhe_sym(id_aa64smfr0_el1_sys_val);
extern unsigned long kvm_nvhe_sym(__icache_flags);
extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits);
extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl);
extern unsigned int kvm_nvhe_sym(hyp_gicv3_nr_lr);
#endif /* __ARM64_KVM_HYP_H__ */
arch/arm64/kvm/arm.c
+2
View File
@@ -2026,6 +2026,8 @@ static int __init init_subsystems(void)
switch (err) {
case 0:
vgic_present = true;
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
kvm_nvhe_sym(hyp_gicv3_nr_lr) = kvm_vgic_global_state.nr_lr;
break;
case -ENODEV:
case -ENXIO:
arch/arm64/kvm/hyp/nvhe/hyp-main.c
+9
View File
@@ -22,6 +22,9 @@
DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
/* Number of implemented GICv3 LRs. Used by flush_hyp_vcpu(). */
unsigned int hyp_gicv3_nr_lr;
void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt);
static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
@@ -46,6 +49,12 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2;
hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3;
/* Bound used_lrs by the number of implemented list registers. */
hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs =
min_t(unsigned int,
hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs,
hyp_gicv3_nr_lr);
}
static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)