From: Halil Pasic <pasic@linux.ibm.com>
Date: Thu, 9 Feb 2023 00:00:22 +0100
Subject: [PATCH] s390: vfio-ap: tighten the NIB validity check
References: bsc#1012628
Patch-mainline: 6.2.3
Git-commit: a64a6d23874c574d30a9816124b2dc37467f3811

[ Upstream commit a64a6d23874c574d30a9816124b2dc37467f3811 ]

The NIB is architecturally invalid if the address designates a
storage location that is not installed or if it is zero.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
Reported-by: Janosch Frank <frankja@linux.ibm.com>
Fixes: ec89b55e3bce ("s390: ap: implement PAPQ AQIC interception in kernel")
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/s390/crypto/vfio_ap_ops.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index b0b25bc9..2bba5ed8 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -349,6 +349,8 @@ static int vfio_ap_validate_nib(struct kvm_vcpu *vcpu, dma_addr_t *nib)
 {
 	*nib = vcpu->run->s.regs.gprs[2];
 
+	if (!*nib)
+		return -EINVAL;
 	if (kvm_is_error_hva(gfn_to_hva(vcpu->kvm, *nib >> PAGE_SHIFT)))
 		return -EINVAL;
 
-- 
2.35.3