diff options
| author | Hyunwoo Kim <imv4bel@gmail.com> | 2026-06-05 05:59:15 +0900 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2026-06-17 12:49:11 +0100 |
| commit | 0074b82cdfcb5fd13710a0ac308ade68ac6f6fbe (patch) | |
| tree | 4b2a0cc609f3f83a2194312eeb86361ce6d6a368 /arch | |
| parent | 7258770e5814f15e8308ebda82ac9acf6964ba8e (diff) | |
KVM: arm64: vgic: Check the interrupt is still ours before migrating it
vgic_prune_ap_list() drops both ap_list_lock and irq_lock while migrating
an interrupt to another vCPU. After reacquiring the locks it only checks
that the affinity is unchanged (target_vcpu == vgic_target_oracle(irq))
before moving the interrupt, which assumes that an interrupt whose affinity
is preserved is still queued on this vCPU's ap_list.
That assumption no longer holds if the interrupt is taken off the ap_list
while the locks are dropped. vgic_flush_pending_lpis() removes the
interrupt from the list and sets irq->vcpu to NULL, but leaves
enabled/pending/target_vcpu untouched. As the interrupt is still enabled
and pending, vgic_target_oracle() returns the same target_vcpu, so the
affinity check passes and list_del() is run a second time on an entry that
has already been removed.
Also check that the interrupt is still assigned to this vCPU
(irq->vcpu == vcpu) before moving it.
Fixes: 0919e84c0fc1 ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Link: https://patch.msgid.link/aiHnI1mu6SGQrgnz@v4bel
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 70a161383e5a..ccb7e3a90cd0 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -820,15 +820,16 @@ retry: raw_spin_lock(&irq->irq_lock); /* - * If the affinity has been preserved, move the - * interrupt around. Otherwise, it means things have - * changed while the interrupt was unlocked, and we - * need to replay this. + * If the interrupt is still ours and its affinity has + * been preserved, move it around. Otherwise, it means + * things have changed while the interrupt was unlocked + * (it may even have been taken off the list with its + * affinity left untouched), and we need to replay this. * * In all cases, we cannot trust the list not to have * changed, so we restart from the beginning. */ - if (target_vcpu == vgic_target_oracle(irq)) { + if (irq->vcpu == vcpu && target_vcpu == vgic_target_oracle(irq)) { struct vgic_cpu *new_cpu = &target_vcpu->arch.vgic_cpu; list_del(&irq->ap_list); |