diff options
| author | Oliver Upton <oliver.upton@linux.dev> | 2024-01-04 21:32:32 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2024-01-04 22:26:34 +0300 |
| commit | ad362fe07fecf0aba839ff2cc59a3617bd42c33f (patch) | |
| tree | f0fabc18b2c1ae7a9202ee2a62d317275c525ba1 /arch | |
| parent | 39084ba8d0fceb477a264e2bb8dfd3553876b84c (diff) | |
| download | linux-ad362fe07fecf0aba839ff2cc59a3617bd42c33f.tar.xz | |
KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache
There is a potential UAF scenario in the case of an LPI translation
cache hit racing with an operation that invalidates the cache, such
as a DISCARD ITS command. The root of the problem is that
vgic_its_check_cache() does not elevate the refcount on the vgic_irq
before dropping the lock that serializes refcount changes.
Have vgic_its_check_cache() raise the refcount on the returned vgic_irq
and add the corresponding decrement after queueing the interrupt.
Cc: stable@vger.kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240104183233.3560639-1-oliver.upton@linux.dev
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic-its.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 2dad2d095160..e2764d0ffa9f 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -590,7 +590,11 @@ static struct vgic_irq *vgic_its_check_cache(struct kvm *kvm, phys_addr_t db, unsigned long flags; raw_spin_lock_irqsave(&dist->lpi_list_lock, flags); + irq = __vgic_its_check_cache(dist, db, devid, eventid); + if (irq) + vgic_get_irq_kref(irq); + raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags); return irq; @@ -769,6 +773,7 @@ int vgic_its_inject_cached_translation(struct kvm *kvm, struct kvm_msi *msi) raw_spin_lock_irqsave(&irq->irq_lock, flags); irq->pending_latch = true; vgic_queue_irq_unlock(kvm, irq, flags); + vgic_put_irq(kvm, irq); return 0; } |