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Wed, 29 Jul 2026 15:29:39 +0000 (GMT) Received: from p-imbrenda.ehn-de.ibm.com (unknown [9.224.75.30]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 29 Jul 2026 15:29:39 +0000 (GMT) From: Claudio Imbrenda To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, linux-s390@vger.kernel.org, borntraeger@de.ibm.com, frankja@linux.ibm.com, david@kernel.org, seiden@linux.ibm.com, nrb@linux.ibm.com, schlameuss@linux.ibm.com, gra@linux.ibm.com Subject: [PATCH v5 04/13] KVM: s390: ucontrol: Fix sca_clear_ext_call() Date: Wed, 29 Jul 2026 17:29:29 +0200 Message-ID: <20260729152938.782383-5-imbrenda@linux.ibm.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260729152938.782383-1-imbrenda@linux.ibm.com> References: <20260729152938.782383-1-imbrenda@linux.ibm.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: B8NQptOVQ7MA1tvV1GhBqWq60fKiaG9G X-Proofpoint-ORIG-GUID: B8NQptOVQ7MA1tvV1GhBqWq60fKiaG9G X-Proofpoint-Spam-Info: AW1haW4tMjYwNzI5MDEyMyBTYWx0ZWRfX6zazywwIgh4/ wucn67uTDXVJqzHv60OcvWt3n+pJPgTCZWu3SG1s+WFtXfcnDOgo0kUWuFm6FyVmkOHJydvzKu9 RmMe5n6omZBqWUBsu8HW5j+5PrbS0+c= X-Authority-Analysis: v=2.4 cv=dYuwG3Xe c=1 sm=1 tr=0 ts=6a6a1c6a cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=U7nrCbtTmkRpXpFmAIza:22 a=VnNF1IyMAAAA:8 a=Ldj-dCDcYccjn2ExLKoA:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzI5MDEyMyBTYWx0ZWRfX83qev/QoCtBq SEXSop6UrYmxhWWWZmP15QCXsIpp3rNapwuGAZHx/a4QhOslDGMO/c2YSsaNO4C39bwXMDITVb5 ftPRu8xWprUPTRqn9SZ/ZYN5cSgZxMWOldoPefTCZswGQF2nRXpq4a2wdXdVHbfunKcQtEoywk+ Cxwxg378SyXgaRObg17qe7iXmJmJOkPyqOnh2gmV69qsIzOLsUs74UvdIvUCM/mfHIqyzT7P+eB SNFFfLBoUjcEV8EE8ONTFW0RtjsEOsPQcbvY36GCMBPzcLAza3I3/tkPYh5+Ov3fsya0PuVb9CW GqMck9e/A+ZYGGKQtXvInKqNfUfpyY4Vyr9+IG4RGSCtzGTaJEkbG8FXExN6WHY8t7xnSOLvHdb P3E+SLSnkC/eUY6fTNiQLoVwWn7V5eZN4uO1NDP2ENJHDNd2aBHQ7+Xi9QlK9nxxpfsFDQml/79 TjBXgAguf967YJIvBBQ== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-29_06,2026-07-29_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 impostorscore=0 clxscore=1015 phishscore=0 malwarescore=0 spamscore=0 lowpriorityscore=0 bulkscore=0 suspectscore=0 adultscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607290123 When cleaning up a UCONTROL VM, sca_clear_ext_call() will touch memory outside of the allocated ESCA block, and UCONTROL VMs don't even use ESCA. Fix by not touching ESCA for UCONTROL VMs. Opportunistically add checks in sca_ext_call_pending() and sca_inject_ext_call() to make sure UCONTROL VMs won't call those functions. Signed-off-by: Claudio Imbrenda Fixes: 7d43bafcff17 ("KVM: s390: Make provisions for ESCA utilization") --- arch/s390/kvm/interrupt.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 2acdff130fa6..d02724bd1829 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -50,6 +50,8 @@ static int sca_ext_call_pending(struct kvm_vcpu *vcpu, int *src_id) if (!kvm_s390_test_cpuflags(vcpu, CPUSTAT_ECALL_PEND)) return 0; + if (KVM_BUG_ON(kvm_is_ucontrol(vcpu->kvm), vcpu->kvm)) + return -EINVAL; BUG_ON(!kvm_s390_use_sca_entries()); if (src_id) @@ -66,6 +68,8 @@ static int sca_inject_ext_call(struct kvm_vcpu *vcpu, int src_id) int expect, rc; BUG_ON(!kvm_s390_use_sca_entries()); + if (KVM_BUG_ON(kvm_is_ucontrol(vcpu->kvm), vcpu->kvm)) + return -EINVAL; old_val = READ_ONCE(*sigp_ctrl); old_val.c = 0; @@ -84,10 +88,13 @@ static int sca_inject_ext_call(struct kvm_vcpu *vcpu, int src_id) static void sca_clear_ext_call(struct kvm_vcpu *vcpu) { struct esca_block *sca = vcpu->kvm->arch.sca; - union esca_sigp_ctrl *sigp_ctrl = &sca->cpu[vcpu->vcpu_id].sigp_ctrl; + union esca_sigp_ctrl *sigp_ctrl; - if (!kvm_s390_use_sca_entries() || !vcpu->arch.initialized) + if (!kvm_s390_use_sca_entries() || !vcpu->arch.initialized || kvm_is_ucontrol(vcpu->kvm)) return; + + /* Initialize after the above check, to prevent going out of bounds */ + sigp_ctrl = &sca->cpu[vcpu->vcpu_id].sigp_ctrl; kvm_s390_clear_cpuflags(vcpu, CPUSTAT_ECALL_PEND); WRITE_ONCE(sigp_ctrl->value, 0); -- 2.55.0