From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f73.google.com (mail-ej1-f73.google.com [209.85.218.73]) (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 D20153D45CF for ; Tue, 23 Jun 2026 11:54:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782215652; cv=none; b=S1qChtXRUh4U/9IPHwbzZkw6RrGY1YQ1erdYHJns90LEWmp1jyYnH0xMsBe0ZGuAfh4dyGo//HbBm7pBJJLGWYJCNN9k7wT5h7mJcm9/vDuDNHHg1MYYYjmlZCyfCsoF3HaMCYCpEGfC1EFb+xA2nT6EcMC4vFnj9JETmTkYvek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782215652; c=relaxed/simple; bh=ZemjVgeFdNSzNMq2VrYAhRUIQEkBVMoaTX9g1MbjW6E=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Pocc7XfDp8hNe+CPlW1WtAAgwqiwBQhdqF7i5yxXgx3HGAQ3uv89Hb9nmEtmeOW+xuVOBzNWV+yQLw2zyhZD4GPt56QLbXxiFmP4hWNFRVjLJDcdHIAgaObxGsz54rxVM7SZTHwS4SyohA2VN1aIWy/L6DD33MV9UlZGaD+QroA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--sebastianene.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Jd7vJjyk; arc=none smtp.client-ip=209.85.218.73 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--sebastianene.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Jd7vJjyk" Received: by mail-ej1-f73.google.com with SMTP id a640c23a62f3a-bf4ba05fd18so134266066b.1 for ; Tue, 23 Jun 2026 04:54:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1782215648; x=1782820448; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=09b+kI/zkikg9+QKQPwRY6ZbJWum8PvSur8NwEqIQDI=; b=Jd7vJjyknAC/DLbvD/yPUBbp08UsEggai6vvi+PE0KWjx5iYvBH1dENUf2dNyTUYG+ Haqstq8h0JTIFsn+g+RGl879KA0QeeoFpXQpOCLA/kyFg8Qqfu16GxulX2tgwfJX44Pr 5/lsK4IdQ6UbFOMN/fQ2x1BpX5HetrYUsGHFoM8V7E8CDGaXBipPIh13MKIckE5jXZIV XrCY2r/Mi3lFqmdGdCo7zs5FT+7cXqZ8SpJlwMAhlcHcH2NyRfwh1KbEZe4Ve7YH2fSq 7Alx7mDWCspHrlPgnePlvQf3SNyGrESgkzrOyh/wbRkTPpdzFc681GuPP0XZraLiUxac rRAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782215648; x=1782820448; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=09b+kI/zkikg9+QKQPwRY6ZbJWum8PvSur8NwEqIQDI=; b=W1q0yCsBBxdzxB7sZH+Tcf79Q6L5QPvVO48wj3ZZb3UHeZQbWdm2RTOUx9mvUOzVXY TlzYrGeWcT0/O/zNKJQ5Icz6Ef9BK6LUu4kx8HkOMnAt8zpI8dKeuuoMjkrQiDR0HD3c wLuVX/MGqgcbH8bdcvW0BvVNL0IayBpFmQKgdCpjK8D4lD3W4Jt6LiLK6xeq9W/83IFU k9VLUwYWLb4YmvjCVdchY9xpSQdzZK+MXthqT820FU/F3Sk7aeY8YC2JH0XAQo5KmVy0 zCB5LlhBQcc5szdHwKf7fwpS5hL8oFosn0ojiZCRlDGMJVfDRMQHRZodlNfnQ6mMg8y4 7TTA== X-Forwarded-Encrypted: i=1; AFNElJ85+ODSdGrYDoRZVgx1cI0mHYsvQFcA8vNqCZwUjBSxyx6hFikzcyjNMsMazKxXo344AO2evNS1Z2os9ks=@vger.kernel.org X-Gm-Message-State: AOJu0YwbLwUv97KthYgnVhg7vO53DhlovRDGJWJYUnIfzqHFxZ2ix3KE ym15hZmme+xZbvIgfQGYvAzjTRxBO8Wa3iXtbjhYZyBCoNfhr/4kjWixsGFBy9tsmfc1lgqS0P3 OQ1BslKFDlsWc07uZkQqKiEEiHYy0oA== X-Received: from ejcse22.prod.google.com ([2002:a17:907:a396:b0:beb:297f:8f09]) (user=sebastianene job=prod-delivery.src-stubby-dispatcher) by 2002:a17:906:6a02:b0:c10:256:3d6a with SMTP id a640c23a62f3a-c107f9a5639mr127032566b.31.1782215647857; Tue, 23 Jun 2026 04:54:07 -0700 (PDT) Date: Tue, 23 Jun 2026 11:53:48 +0000 In-Reply-To: <20260623115354.632361-1-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260623115354.632361-1-sebastianene@google.com> X-Mailer: git-send-email 2.55.0.rc0.786.g65d90a0328-goog Message-ID: <20260623115354.632361-2-sebastianene@google.com> Subject: [PATCH v5 1/7] KVM: arm64: Enforce strict SBZ checks in the FF-A proxy From: Sebastian Ene To: catalin.marinas@arm.com, maz@kernel.org, oupton@kernel.org, will@kernel.org Cc: joey.gouly@arm.com, korneld@google.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, android-kvm@google.com, mrigendra.chaubey@gmail.com, perlarsen@google.com, sebastianene@google.com, suzuki.poulose@arm.com, vdonnefort@google.com, yuzenghui@huawei.com Content-Type: text/plain; charset="UTF-8" Introduce a helper method ffa_check_unused_args_sbz to enforce strict arguments checking when the hypervisor acts as a relayer between the host and Trustzone. Signed-off-by: Sebastian Ene Reviewed-by: Vincent Donnefort --- arch/arm64/kvm/hyp/nvhe/ffa.c | 54 +++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 1af722771178..78bb043b33ee 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -71,6 +71,20 @@ static u32 hyp_ffa_version; static bool has_version_negotiated; static hyp_spinlock_t version_lock; +static bool ffa_check_unused_args_sbz(struct kvm_cpu_context *ctxt, int first_reg) +{ + DECLARE_REG(u32, func_id, ctxt, 0); + int reg, end_reg; + + end_reg = ARM_SMCCC_IS_64(func_id) ? 17 : 7; + for (reg = first_reg; reg <= end_reg; reg++) { + if (cpu_reg(ctxt, reg)) + return true; + } + + return false; +} + static void ffa_to_smccc_error(struct arm_smccc_1_2_regs *res, u64 ffa_errno) { *res = (struct arm_smccc_1_2_regs) { @@ -239,6 +253,11 @@ static void do_ffa_rxtx_map(struct arm_smccc_1_2_regs *res, int ret = 0; void *rx_virt, *tx_virt; + if (ffa_check_unused_args_sbz(ctxt, 4)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + if (npages != (KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) / FFA_PAGE_SIZE) { ret = FFA_RET_INVALID_PARAMETERS; goto out; @@ -315,6 +334,11 @@ static void do_ffa_rxtx_unmap(struct arm_smccc_1_2_regs *res, DECLARE_REG(u32, id, ctxt, 1); int ret = 0; + if (ffa_check_unused_args_sbz(ctxt, 2)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + if (id != HOST_FFA_ID) { ret = FFA_RET_INVALID_PARAMETERS; goto out; @@ -421,6 +445,11 @@ static void do_ffa_mem_frag_tx(struct arm_smccc_1_2_regs *res, int ret = FFA_RET_INVALID_PARAMETERS; u32 nr_ranges; + if (ffa_check_unused_args_sbz(ctxt, 5)) { + ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS); + return; + } + if (fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) goto out; @@ -482,6 +511,11 @@ static void __do_ffa_mem_xfer(const u64 func_id, u32 offset, nr_ranges, checked_offset; int ret = 0; + if (ffa_check_unused_args_sbz(ctxt, 5)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out; + } + if (addr_mbz || npages_mbz || fraglen > len || fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { ret = FFA_RET_INVALID_PARAMETERS; @@ -581,6 +615,11 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, int ret = 0; u64 handle; + if (ffa_check_unused_args_sbz(ctxt, 4)) { + ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS); + return; + } + handle = PACK_HANDLE(handle_lo, handle_hi); hyp_spin_lock(&host_buffers.lock); @@ -769,6 +808,11 @@ static void do_ffa_version(struct arm_smccc_1_2_regs *res, { DECLARE_REG(u32, ffa_req_version, ctxt, 1); + if (ffa_check_unused_args_sbz(ctxt, 2)) { + res->a0 = FFA_RET_NOT_SUPPORTED; + return; + } + if (FFA_MAJOR_VERSION(ffa_req_version) != 1) { res->a0 = FFA_RET_NOT_SUPPORTED; return; @@ -818,6 +862,11 @@ static void do_ffa_part_get(struct arm_smccc_1_2_regs *res, DECLARE_REG(u32, flags, ctxt, 5); u32 count, partition_sz, copy_sz; + if (ffa_check_unused_args_sbz(ctxt, 6)) { + ffa_to_smccc_res(res, FFA_RET_INVALID_PARAMETERS); + return; + } + hyp_spin_lock(&host_buffers.lock); if (!host_buffers.rx) { ffa_to_smccc_res(res, FFA_RET_BUSY); @@ -890,6 +939,11 @@ bool kvm_host_ffa_handler(struct kvm_cpu_context *host_ctxt, u32 func_id) switch (func_id) { case FFA_FEATURES: + if (ffa_check_unused_args_sbz(host_ctxt, 3)) { + ffa_to_smccc_res(&res, FFA_RET_INVALID_PARAMETERS); + goto out_handled; + } + if (!do_ffa_features(&res, host_ctxt)) return false; goto out_handled; -- 2.55.0.rc0.786.g65d90a0328-goog