[PATCH 6.12 0861/1102] KVM: PPC: Book3S HV: Set irqfd->producer only on success

6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: leixiang <redacted>

commit 1144454ea22290d7c6998a2af6239e5995476afc upstream.

Set irqfd->producer only after kvmppc_set_passthru_irq() succeeds to
avoid leaving a dangling pointer on failure. The bypass manager does
not register a failed producer, so the pointer is never cleared.

Fixes: c57875f5f9be ("KVM: PPC: Book3S HV: Enable IRQ bypass")
Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: leixiang <redacted>
Reviewed-by: Amit Machhiwal <redacted>
Reviewed-by: Vaibhav Jain <redacted>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260709055755.31297-1-leixiang@kylinos.cn (local)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/powerpc/kvm/book3s_hv.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c

@@ -6069,12 +6069,12 @@ static int kvmppc_irq_bypass_add_produce
 	struct kvm_kernel_irqfd *irqfd =
 		container_of(cons, struct kvm_kernel_irqfd, consumer);
 
-	irqfd->producer = prod;
-
 	ret = kvmppc_set_passthru_irq(irqfd->kvm, prod->irq, irqfd->gsi);
 	if (ret)
 		pr_info("kvmppc_set_passthru_irq (irq %d, gsi %d) fails: %d\n",
 			prod->irq, irqfd->gsi, ret);
+	else
+		irqfd->producer = prod;
 
 	return ret;
 }