From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 094263905F8 for ; Tue, 12 May 2026 12:44:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778589896; cv=none; b=KsL6GdKCJnWm9EvE+PdjEdZsHznKgsjVoTg0Ce37QCcOXfYlrr2gq3Yt0K2c54GSQh8AAK6SJpgXr9fkjAXvv5gNyGBfMeAW3ywDq0Rex132oKyUyOOyr5f28YQR9l2gVTqCa4DawogVhLNcYpSXkA35Zpc1+xVcai/NxxVHvzk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778589896; c=relaxed/simple; bh=bKVcDqwHwK/xbpDT9Uz7ToiCHD6FOj4O/mRSqjJ7G0Y=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=KThLU01oojILa9e/3pfiiHlcCWgg6YIJ1LzYWw7O/oiFFt0h86WAaxKYqjYte1lUTELELcwEXnQ4cQPJ4SJIglWuJhnLgz9m/X/bL4P9BxlHBgspVUkNTej912kzFsugPQLt/6cHzdY1IxG9FTQuCw5B2y+TLDOwE+2L8YclFdk= 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=GAtZorNz; arc=none smtp.client-ip=209.85.128.74 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="GAtZorNz" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-48fb4ffebe7so136955e9.0 for ; Tue, 12 May 2026 05:44:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778589886; x=1779194686; 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=NTRlEigdkhn6bOKBOZmqHGKnjSXcZHjG0+RY5EH/5oA=; b=GAtZorNz0q9mXJJOIxqrAE9SLTc4/AcxV3aQkinIXVjao2ZtBQdpxjjJdqbGiZgPQu n3jSMc19ABoxnyqt258ZzOY/zuffxhchX/syM5amwdvfsKVBfAS0fqqzcNn0gkCrlZfL zYEoW2eBfRju7jQcp3/nTqgWwnvguhe5aoZVG9aNMlrgCRuwp+nnXaVOdNrNEDR65ptH 2hCICJedfo9FxTKqVKkfmkssTkgRAsRfYsJxGZkStzGEQfQha2Y+Y0Dm/vh8Jy3C7Ocv XbAb72mf60WRaX/1WpHwJjyfO6dGPQ9ATtO9O4ngKOR2/96fbOH914MV6VW9gBeB53fr LSug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778589886; x=1779194686; 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=NTRlEigdkhn6bOKBOZmqHGKnjSXcZHjG0+RY5EH/5oA=; b=ha2GpzOlNBViUX+0GwhoEPE8m9q3FPBFaKTSdG4ab9S/7279t/fWhRXnQJqrlkd4Df Pieub8yNb75D2ybyhmUfE4XUvSsG0enmfhDhX6JQdGWLBDpAazKZOV+e4vvdI42adNJn jebBO2tNaTHq3UY952T8c/7wsaRnrSgAzMaOoXbvmHvQktSs9ilOrQboZB/CTiuZF5zR w76pZXxElWTUkBQrunciKMjmRoVdkKWO4e4UEbaAoNtQAul/lTjw8m8z1W8JYYJ3ICly yCmPR9IVWeZ8oRiB2kiNstP4FMemurR8HJcZSRz3WcmOa++7SGawsetSTqty3wzwS+hz K8ig== X-Forwarded-Encrypted: i=1; AFNElJ/9UaKxoFW55XRfk1sVIlN7s+iL80xsX4QxCB5WpwsTfcfslMBkM+crPPK2opGwUvT1UeR++bpivGlZdf8=@vger.kernel.org X-Gm-Message-State: AOJu0YyybfvaA34KayEcojOHeEhdkj8zBwX+ktNPejr75Z/EvOjpDGNa RO8UBxXjIQuivRgSN8PZjgLcA4bS+dUvcwb8SfCpXLqx/HFf35zOZqjnY+KoyOFOYE52ha9hAB4 JsXbl3xOBuWincVo/DUQBy31weUlj5w== X-Received: from wrpy15.prod.google.com ([2002:adf:f6cf:0:b0:43d:7331:91dd]) (user=sebastianene job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:6211:b0:48a:5301:bb5c with SMTP id 5b1f17b1804b1-48e8fe72215mr45081965e9.16.1778589886397; Tue, 12 May 2026 05:44:46 -0700 (PDT) Date: Tue, 12 May 2026 12:44:42 +0000 In-Reply-To: <20260512124442.1899107-1-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260512124442.1899107-1-sebastianene@google.com> X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: <20260512124442.1899107-3-sebastianene@google.com> Subject: [PATCH v3 2/2] KVM: arm64: Validate the offset to the mem access descriptor From: Sebastian Ene To: catalin.marinas@arm.com, maz@kernel.org, oupton@kernel.org, sudeep.holla@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" Prevent the pKVM hypervisor from making assumptions that the endpoint memory access descriptor (EMAD) comes right after the FF-A memory region header. Prior to FF-A version 1.1 the header of the memory region didn't contain an offset to the endpoint memory access descriptor. The layout of a memory transaction looks like this from 1.1 onward: Type | Field name | Offset [ Header | ffa_mem_region | 0 EMAD 1 | ffa_mem_region_attributes) | ffa_mem_region.ep_mem_offset ] Verify that the offset to the first endpoint memory access descriptor is within the mailbox buffer bounds. Signed-off-by: Sebastian Ene --- arch/arm64/kvm/hyp/nvhe/ffa.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 1af722771178..34927bc1239b 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -479,7 +479,7 @@ static void __do_ffa_mem_xfer(const u64 func_id, struct ffa_mem_region_attributes *ep_mem_access; struct ffa_composite_mem_region *reg; struct ffa_mem_region *buf; - u32 offset, nr_ranges, checked_offset; + u32 offset, nr_ranges, checked_offset, em_mem_access_off; int ret = 0; if (addr_mbz || npages_mbz || fraglen > len || @@ -508,8 +508,14 @@ static void __do_ffa_mem_xfer(const u64 func_id, buf = hyp_buffers.tx; memcpy(buf, host_buffers.tx, fraglen); - ep_mem_access = (void *)buf + - ffa_mem_desc_offset(buf, 0, hyp_ffa_version); + em_mem_access_off = ffa_mem_desc_offset(buf, 0, hyp_ffa_version); + if (em_mem_access_off > + KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE - sizeof(struct ffa_mem_region_attributes)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + ep_mem_access = (void *)buf + em_mem_access_off; offset = ep_mem_access->composite_off; if (!offset || buf->ep_count != 1 || buf->sender_id != HOST_FFA_ID) { ret = FFA_RET_INVALID_PARAMETERS; @@ -576,7 +582,7 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, DECLARE_REG(u32, flags, ctxt, 3); struct ffa_mem_region_attributes *ep_mem_access; struct ffa_composite_mem_region *reg; - u32 offset, len, fraglen, fragoff; + u32 offset, len, fraglen, fragoff, em_mem_access_off; struct ffa_mem_region *buf; int ret = 0; u64 handle; @@ -599,8 +605,14 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, len = res->a1; fraglen = res->a2; - ep_mem_access = (void *)buf + - ffa_mem_desc_offset(buf, 0, hyp_ffa_version); + em_mem_access_off = ffa_mem_desc_offset(buf, 0, hyp_ffa_version); + if (em_mem_access_off > + KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE - sizeof(struct ffa_mem_region_attributes)) { + ret = FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + ep_mem_access = (void *)buf + em_mem_access_off; offset = ep_mem_access->composite_off; /* * We can trust the SPMD to get this right, but let's at least -- 2.54.0.563.g4f69b47b94-goog