From nobody Tue Apr 7 14:36:44 2026 Received: from mail-pg1-f201.google.com (mail-pg1-f201.google.com [209.85.215.201]) (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 D4B9228DB49 for ; Fri, 13 Mar 2026 00:33:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773361990; cv=none; b=YL0bKGlpgZQQuyj8fxVioS3qtmIzibdbUstlyu/14c9OKAKk0b1oRmrLi6WJe5UFrwZbKaWN9Ft9yHuHua5gaE81Gfvzv67sRhZRrX2RTd3HoaR0SiMtzRnyVN3QK1b9MsGHmGJQ6VAfQ0xn3PNHPZVXt1LcT7dSAhPZr/ZKwdk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773361990; c=relaxed/simple; bh=ugj8UDoOW98hDBU9yiqY9dU7o/bzNnqLvw5mzSYorEs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=c/7hIfLB058RhqBIzKXuK99F9feV2JS+DaKM6J8lb6r2UIWhLyIz0fr4XIV8pik6yPsPdErP3mPlWaCpldfQKDpXrI4p8reNdRbAB8sM5ps6BssopRurif+lmO4pcuHcw2XMUTm9TERjYXtRguzf3KlX2J05qSboPBew3MJqFbs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Dm78ReDp; arc=none smtp.client-ip=209.85.215.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Dm78ReDp" Received: by mail-pg1-f201.google.com with SMTP id 41be03b00d2f7-c737b6686ddso1063088a12.3 for ; Thu, 12 Mar 2026 17:33:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1773361988; x=1773966788; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=JDd4PhY9bJhpZgSv4RiGr3oEGXZFNbQJpQq76MQNlqg=; b=Dm78ReDpKfXORPZgTQymJB47AZpkva6Qnet9d+OBF4Jgs8MiAVLvIngpP24qDoRkAP wju35QjXqrsy5swtKbt6gvyo9KDAoEuvRWm+qfbWO0zYb95KSF4t85zB2dbwuXblIB24 zb9AhfawFwavK+S2SqTX8fqNQ7KBRHHFFCGCOrGwmYKJj/Jm4grSKunejNy1zU6M6TK3 Ipoe2FSUww0ztJP6U8yTtpnr5+8QXme7laOvdlJpJpvR3yEKG09yHcCed25WNlkfmbUS 6PlhA40mbbPxlxRoS9RdQLKwF1uT5vbKdgOqMXKPI8sN1JJVK+eRlZz5ofZpYZy325uO K1bg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1773361988; x=1773966788; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=JDd4PhY9bJhpZgSv4RiGr3oEGXZFNbQJpQq76MQNlqg=; b=DweBvtjEwQIgxkd1q7tpBj9CXVn0KjGvvl8gwqXT9p7vNW7bxSlKqYNnWp3FXTXx/8 7MspNWAqkeFmMfBiFL1ErZKb1/0nZJZiT8Ho2glhihnT+c4OSQ4kDnpfDkMK3Smj3nCU eLpNw3buykj1VbMWvr0nqDxwJy4dXHGd6w0veYrPOauxMVoPwd65264wwIK2aYp/PONA X8rpdms3F11xBDV23zEuZfAAInEBxYrDadfJuAxXt5mjJbQrRMRSIvCprPB+TgxPRJfX ouvIYRpt/x3WVUL+8Fq7PXo6QOFgDqgBQoI5zCcOOIke8/HnEBQjmT+1w55LF3Fhn1RV wnrg== X-Forwarded-Encrypted: i=1; AJvYcCWuaAudrzuydFnz/YYhNeStpgN3reuLhOM2ebOeoLJvEMzEjx90/gokOnCSjire2/Koe5eRuZw6biTT/DQ=@vger.kernel.org X-Gm-Message-State: AOJu0YxNFFHvV+7kDoOyKAEg9xbEOM9ADRBVczWRvoRpCIQ7C0ESKHPM RoWTkaJ/KlxFwwtwUG/sswt05y1JKS/FBP3Pkx5ELgoWhVEt9n6MOGaofT6gqe29axriVDw2VJ4 aOlz3TA== X-Received: from pgmj24.prod.google.com ([2002:a63:5958:0:b0:c6e:3f59:895e]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a21:3981:b0:398:9c2b:c92c with SMTP id adf61e73a8af0-398ecadefdbmr972992637.27.1773361987985; Thu, 12 Mar 2026 17:33:07 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 12 Mar 2026 17:32:59 -0700 In-Reply-To: <20260313003302.3136111-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260313003302.3136111-1-seanjc@google.com> X-Mailer: git-send-email 2.53.0.851.ga537e3e6e9-goog Message-ID: <20260313003302.3136111-3-seanjc@google.com> Subject: [PATCH 2/5] KVM: SEV: Drop useless sanity checks in sev_mem_enc_register_region() From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Liam Merwick Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Drop sev_mem_enc_register_region()'s sanity checks on the incoming address and size, as SEV is 64-bit only, making ULONG_MAX a 64-bit, all-ones value, and thus making it impossible for kvm_enc_region.{addr,size} to be greater than ULONG_MAX. Note, sev_pin_memory() verifies the incoming address is non-NULL (which isn't strictly required, but whatever), and that addr+size don't wrap to zero (which _is_ needed and what really needs to be guarded against). Note #2, pin_user_pages_fast() guards against the end address walking into kernel address space, so lack of an access_ok() check is also safe (maybe not ideal, but safe). No functional change intended (the generated code is literally the same, i.e. the compiler was smart enough to know the checks were useless). Signed-off-by: Sean Christopherson --- arch/x86/kvm/svm/sev.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 23a383f2e43d..857771586f16 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -2711,9 +2711,6 @@ int sev_mem_enc_register_region(struct kvm *kvm, if (is_mirroring_enc_context(kvm)) return -EINVAL; =20 - if (range->addr > ULONG_MAX || range->size > ULONG_MAX) - return -EINVAL; - region =3D kzalloc_obj(*region, GFP_KERNEL_ACCOUNT); if (!region) return -ENOMEM; --=20 2.53.0.851.ga537e3e6e9-goog