diff options
| author | Oliver Upton <[email protected]> | 2024-01-04 18:32:32 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2024-01-25 14:37:53 -0800 |
| commit | ba7be666740847d967822bed15500656b26bc703 (patch) | |
| tree | dad7505b6a3e9643c28f7c878dd718d3a932a900 | |
| parent | 9b5a278594b9c97438adce4b704148f55de0ece0 (diff) | |
| download | linux-ba7be666740847d967822bed15500656b26bc703.tar.gz | |
KVM: arm64: vgic-its: Avoid potential UAF in LPI translation cache
commit ad362fe07fecf0aba839ff2cc59a3617bd42c33f upstream.
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: [email protected]
Signed-off-by: Oliver Upton <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
| -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 23710bf5a86b6d..62f261b8eb62f6 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -584,7 +584,11 @@ 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; @@ -763,6 +767,7 @@ 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; } |