From nobody Sat Apr 18 06:56:13 2026 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D1BBA331219 for ; Tue, 10 Feb 2026 07:25:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770708341; cv=none; b=OEGzkrLDir/Xrw6Arf81HNORxrNP3qtjCcgsbTHmL3XqOfh3JWwzipyQmJOJhEtX1EdXY1ZgeKlF1p81H7E0+yKnm667cF77n7ZQio0VFPt/1Q49aFFFLYevutIsonUPbf8PAPX312wiFu+KTlLPmYUk1A9cYVLbSlrY/ObBlVI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770708341; c=relaxed/simple; bh=D79oDfikccmJTO2nzCKp5nyOQP5H0uAsjYlZUbPUbB4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=L7H4ouW4EscwZFk/GXuIM0LTVrJZsZVmN0BWkikSvGEbe5GydpARoBTypuP2afUEPtv2d23VF32dd3Rm1lYxq9dXjYTIdGZQhwVVtKJ0EaHaNg1QNdmd1dq90bq7PhBZZMpLW+MsMLYchorrj/js+gJKGGNQykpkI6OE7ivrzI8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ooseel.net; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.214.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ooseel.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-2aadac3e23dso11007875ad.2 for ; Mon, 09 Feb 2026 23:25:39 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770708339; x=1771313139; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NlIK6Drh5/5Im48t/VJk8VIZOF2y0mJxE9VOY1y6hzY=; b=fzuJmb4OKeM0G+nGSsAjxcNnmgC3AKMZ7SqF+4W1wKlyQVprm9QuW4+298HABOHV0x znoXr8OUpPz2zm3gE8jakV+HH//Xp8s2wZEzHTykwAerGqd6yG8qFDs5jnscsQrS4pBp 2zuMB+SoTx+aJgrckP0d4zU9AocJfryu23KmuQk06aifG8j5zv1bP9oe6ivaENhtU+5i mO7rvAcAO9CmguEJ6jBpkt6NFWmZNTFVrfbIBheYKP1nnrbAGP/lZH5V3GM6NrHSeGnW 1lr2sgMW5bA87gRe7Wlf9Ce8ehMFnLYLl6K08INARTtmmqnuIL7y0p8/RuLHkcWnh0vY GvdQ== X-Forwarded-Encrypted: i=1; AJvYcCU+QdptcjeGeRicLDulgSjNIPxl+vtkkSE6W+GllmaUvCISV5jzYyUXMCjU6haTlt2V0UNzF+Km8sFFyl4=@vger.kernel.org X-Gm-Message-State: AOJu0Yz3grt1JwelLBOO6RA+s/MNWyHtEV/AcYn4v57Lt1yWgZ+wChq7 n0H5in9hWUA9w9Vjcugur4wiLPo9LV2F0IViQFNm7vGqH8pNBaghItnuLtJ4LA== X-Gm-Gg: AZuq6aLEEPn/gmH5fIgIonJXNV0xjk1aLgvl7Zpz0rk2RyasqsrgwYNoO9yI7oI7dKK vt0PXzlH0zOi6OLnqojGUej9F+7enCe5KBgKx9cp3FFjy2orzynQUXOGUB4jBAeRUh3jLNspt/G 7VyRxcdPZXt1kBuTRTx7TYyzVU2yDoH6t9rUa3Uf8BjBIV8WlybNGCarwrQNJ4Zb94JbSlHiYDK 2K1Bu1anEUJOWweOdf90TCLUAP44XQd6+pR/O2LgoK0tQ1Aqq69PjfiZL3VWplQc1+nuUT4t/dd 91c1bgWvneypEfrejQkZMxrq0KbXzW1IxX1bDhSc+njRFs3x9QkqThyUTdVMcaBWFneLC1TDUef ZoERw30l5AfAxY3Q2i24iBUjzpA38BsA2Fde21ITwzmRMoKR6koyOa0uPfj0uf+DSsFi7qiQHxJ rZN01ruzwbSrTZ7g== X-Received: by 2002:a17:902:e88d:b0:2a1:e19:ff4 with SMTP id d9443c01a7336-2a9516f5a0bmr130714385ad.29.1770708339174; Mon, 09 Feb 2026 23:25:39 -0800 (PST) Received: from MILKYWAY ([1.213.237.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2a9521b9bebsm125323425ad.56.2026.02.09.23.25.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Feb 2026 23:25:38 -0800 (PST) From: Leesoo Ahn To: lsahn@ooseel.net Cc: Paolo Bonzini , kvm@vger.kernel.org (open list:KERNEL VIRTUAL MACHINE (KVM)), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v1] KVM: Use memdup_user instead of kernel stack to allocate kvm_guest_debug Date: Tue, 10 Feb 2026 16:25:30 +0900 Message-ID: <20260210072530.918038-1-lsahn@ooseel.net> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Switch to using memdup_user to allocate its memory because the size of kvm_guest_debug is over 512 bytes on Arm64 and is burdened allocation from kernel stack. Signed-off-by: Leesoo Ahn --- virt/kvm/kvm_main.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5b5b69c97665..bc0a53129df7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4592,12 +4592,15 @@ static long kvm_vcpu_ioctl(struct file *filp, break; } case KVM_SET_GUEST_DEBUG: { - struct kvm_guest_debug dbg; + struct kvm_guest_debug *dbg; =20 - r =3D -EFAULT; - if (copy_from_user(&dbg, argp, sizeof(dbg))) + dbg =3D memdup_user(argp, sizeof(*dbg)); + if (IS_ERR(dbg)) { + r =3D PTR_ERR(dbg); goto out; - r =3D kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, &dbg); + } + r =3D kvm_arch_vcpu_ioctl_set_guest_debug(vcpu, dbg); + kfree(dbg); break; } case KVM_SET_SIGNAL_MASK: { --=20 2.51.0