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AJvYcCUBdFFSIyUkdlYud8v0Kq7DKtRBrxEQGEHQbRV5E8XcW6XP7CiTrC09V66c1gFh61Vr7QDH6ZYGzV4U@vger.kernel.org X-Gm-Message-State: AOJu0YxUtVTUt7vzjvLQkaPxTWYJSrJkU5M+TkeGF4qlCbAh8MpbfXw0 B948IpKolv6KLXzFyvbK7fUlSIJHHX0msUHRSFxo0XeQx1HAzYqrTt13l5Kao1GlLxaKsuk0dZP Z6QMnQg== X-Received: from dlbvg27.prod.google.com ([2002:a05:7022:7f1b:b0:128:d754:39d]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:41a8:b0:127:33e0:ea33 with SMTP id a92af1059eb24-12a726b3177mr4054533c88.22.1774158199330; Sat, 21 Mar 2026 22:43:19 -0700 (PDT) Date: Sat, 21 Mar 2026 22:43:07 -0700 In-Reply-To: <20260322054309.898214-1-surenb@google.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260322054309.898214-1-surenb@google.com> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Message-ID: <20260322054309.898214-4-surenb@google.com> Subject: [PATCH v4 3/4] KVM: s390: avoid kvm_s390_handle_pv() error overwrite From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: willy@infradead.org, david@kernel.org, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, ying.huang@linux.alibaba.com, apopple@nvidia.com, lorenzo.stoakes@oracle.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, vbabka@suse.cz, jannh@google.com, rppt@kernel.org, mhocko@suse.com, pfalcato@suse.de, kees@kernel.org, maddy@linux.ibm.com, npiggin@gmail.com, mpe@ellerman.id.au, chleroy@kernel.org, borntraeger@linux.ibm.com, frankja@linux.ibm.com, imbrenda@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, svens@linux.ibm.com, gerald.schaefer@linux.ibm.com, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" If kvm_s390_handle_pv() call fails its error code gets recorded but execution proceeds as if the call was successful. If the next call to copy_to_user() fails then the original error is overwritten. The follow-up patch adds fatal signal checks during VMA walk, which makes it possible for kvm_s390_handle_pv() to return EINTR error. Without this fix any error including EINTR can be overwritten and original error will be lost. Change error handling for kvm_s390_handle_pv() to alter normal flow once failure happens. This is consistent with how kvm_arch_vm_ioctl handles errors for other ioctl commands. Signed-off-by: Suren Baghdasaryan --- arch/s390/kvm/kvm-s390.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 3eb60aa932ec..ddad08c0926f 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -2947,6 +2947,8 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) } /* must be called without kvm->lock */ r = kvm_s390_handle_pv(kvm, &args); + if (r) + break; if (copy_to_user(argp, &args, sizeof(args))) { r = -EFAULT; break; -- 2.53.0.1018.g2bb0e51243-goog