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 5E108428462 for ; Wed, 27 May 2026 15:02:47 +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=1779894170; cv=none; b=uFqOagvYyNxWiiPnLVez2vvSPDMYuD9D8NTCZopWLfiIiA6OwgLjjpvhncBWDEeybB2Rp6n/g4YsVnWUWgySgo1EfKGSQc0tWxrbGO4wIoRQ7LaGoSAWwN9HoECpj1+kjlu6Ix6RIzzcLmkGs7Stu+NYhxuwkXmrYC4XnJQqLsM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779894170; c=relaxed/simple; bh=15nq+W4QtQnuAmCVcxh2XcM8fl+7JmCCyFIX1NGjd4w=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=T4Zl6L0eIHgc/YG02kr03i0lfJfHRiaikJa6QiPIWQeCrAbp6H2rpf9upvXdUQ6kDiZC7DoXsMeF3fs+IX5juHAIphPNnxink0VOyv0gA93d14vBDLxUNubZ3A/xnjwxkcgIbVz/du6jklAoFqWb5vraSOjIaVWLoryE0xZtbK0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--smostafa.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=HUhBVxdo; 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--smostafa.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="HUhBVxdo" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-48fdad6cce4so59317435e9.1 for ; Wed, 27 May 2026 08:02:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779894165; x=1780498965; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ZKy2nPJ+cV4SO6crenI0U9khbA/AjfYfGtFJYOFvACc=; b=HUhBVxdo9Vmc5yYFRJu9mIjNSS+ENcYx7BAn/sCNuidW6ZGMnGKypqcXHq/WpG7dTM y8+gtz4v5DDw2auA1gfFx2fgTHAp/ib2UPTqE71IW2dtZodOgTkefVviO1Niv6+1OtMO 6WzewMyHOnH7hrZkbb08fP8e1yC9ufjIDcZgfgR88DZhW73Ceh4kA3pBSEwsPU2FzeKW rBgnm+cHwatRgrHzm2OG9tEcD2Q+lNYvffTaaQB58qS5jA8AZngRFcjagGUYawoED23U QyoBd9PGDFITa3MdP+Uc1SEClDuiy55nJHxLleOIXaL781d80u8w0DJIt1H6G/3Q5Lox 4H8w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779894165; x=1780498965; 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=ZKy2nPJ+cV4SO6crenI0U9khbA/AjfYfGtFJYOFvACc=; b=EBFZkdJXSkMz2jJzxl4jQHgm6M8Y/hU/uBzQ9a2BKeX+tUj4w/yzjn4TN8DxGSUxRw yQREbg5k+Bvv4Ep7CI/2UCsNQKy272CIy348H57GgiZbPmNzEbuKckK683aIpWv9p1ls rMUsscRmowhvGmgT5ZH2GBw4tziSxa66a43ftFudtIDX6bclwc0XVVj4GbxNqGVd8NiR 2xgisB7rc9R8/0DTVpHu/0yZaj3GGnVx+wyZFc4k04ov/hfOqTRPu0jOAOthZvenBwHQ YrriAnbPqWZLTwghEbvAzMgaoudCANu7dsPnHpTd8//1gJDr3NHHF4QYm7GfkqUtuNo7 D12g== X-Forwarded-Encrypted: i=1; AFNElJ/UceVnNFqIsSilpYSCHBIyQOKF63SO8ubzv9dGtPrETSMcCtKO8M/JNg43Y2sqJ/MAMHqTttg=@lists.linux.dev X-Gm-Message-State: AOJu0Yyfw43NIShIi1UUYcV6g3myn4+CLLo7LcbDjhq8bqz/wc/rDTtm fbd3C22u02tY240Zy9zP9r9H2UHBwjmwqs+SZkAuMvpjgvER9+aL5baMpeyzEFE0FE/dkRTuR5c TgfOKYBv+486COQ== X-Received: from wmon5.prod.google.com ([2002:a05:600c:4645:b0:489:1b1b:132]) (user=smostafa job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:2a8b:b0:489:1abb:5559 with SMTP id 5b1f17b1804b1-4904226d9camr214273595e9.5.1779894165174; Wed, 27 May 2026 08:02:45 -0700 (PDT) Date: Wed, 27 May 2026 15:02:34 +0000 In-Reply-To: <20260527150236.1978655-1-smostafa@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260527150236.1978655-1-smostafa@google.com> X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Message-ID: <20260527150236.1978655-5-smostafa@google.com> Subject: [PATCH v6 4/6] KVM: arm64: Fix bounds checking in do_ffa_mem_reclaim() From: Mostafa Saleh To: op-tee@lists.trustedfirmware.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, catalin.marinas@arm.com, jens.wiklander@linaro.org, sumit.garg@kernel.org, sebastianene@google.com, vdonnefort@google.com, sudeep.holla@kernel.org, Mostafa Saleh Content-Type: text/plain; charset="UTF-8" Sashiko (locally) reports out of bound write possiblity if SPMD returns an invalid data. While SPMD is considered trusted, pKVM does some basic checks, for offset to be less than or equal len. However, that is incorrect as even if the offset is smaller than len pKVM can still access out of bound memory in the next ffa_host_unshare_ranges(). Split this check into 2: 1- Check that the fixed portion of the descriptor fits. 2- After getting reg, check the variable array size addr_range_cnt fits. Also, drop the WARN_ONs as that will panic the kernel and in the next checks there are no WARNs, so that makes it consistent. Fixes: 0a9f15fd5674 ("KVM: arm64: pkvm: Add support for fragmented FF-A descriptors") Signed-off-by: Mostafa Saleh --- arch/arm64/kvm/hyp/nvhe/ffa.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c index 1af722771178..b6cf9ad82e12 100644 --- a/arch/arm64/kvm/hyp/nvhe/ffa.c +++ b/arch/arm64/kvm/hyp/nvhe/ffa.c @@ -607,8 +607,8 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, * check that we end up with something that doesn't look _completely_ * bogus. */ - if (WARN_ON(offset > len || - fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE)) { + if (offset + CONSTITUENTS_OFFSET(0) > len || + fraglen > KVM_FFA_MBOX_NR_PAGES * PAGE_SIZE) { ret = FFA_RET_ABORTED; ffa_rx_release(res); goto out_unlock; @@ -641,6 +641,11 @@ static void do_ffa_mem_reclaim(struct arm_smccc_1_2_regs *res, goto out_unlock; reg = (void *)buf + offset; + if (offset + CONSTITUENTS_OFFSET(reg->addr_range_cnt) > len) { + ret = FFA_RET_ABORTED; + goto out_unlock; + } + /* If the SPMD was happy, then we should be too. */ WARN_ON(ffa_host_unshare_ranges(reg->constituents, reg->addr_range_cnt)); -- 2.54.0.746.g67dd491aae-goog