From nobody Sun Feb 8 05:47:53 2026 Received: from mail-ed1-f73.google.com (mail-ed1-f73.google.com [209.85.208.73]) (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 83A972550A4 for ; Fri, 17 Oct 2025 07:57:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760687845; cv=none; b=LstmiD1GdRUlJXLrfq+bW3l8vpLKw9UmW6z1nHxBoJJAG1s/Nu8ANMbpgeBSJkQDug6rdZPnM4M2FGi7Ljzefoy7AEf1WnMN6RA/Nh4cPZA51To4wUBifcE0oZmHTehFYedinnSDqoPavayxQUB9a6bY47/gII3tekutug6QBrs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760687845; c=relaxed/simple; bh=v+cwEQu/l0K0aFYXom/va+vqcAeLTQs97OiCDReEkHw=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=WjrxpTIEIIBhOnQ1E0FscIiYigBDH7e0FLpzQRShe5+G3WrLVMoGz7DovwJwRZjcI8Q6Xm470WVKmgZURyuCRb3iIsN7nxJ3nWXJTOsKy20geNMBaMbkJgYAutzR2xiiBryVzcIUx+GX++irWK4tGLUD7ey7j85lhEBq67Gi+XA= 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=vVDFZY74; arc=none smtp.client-ip=209.85.208.73 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="vVDFZY74" Received: by mail-ed1-f73.google.com with SMTP id 4fb4d7f45d1cf-62fcb646334so2302195a12.2 for ; Fri, 17 Oct 2025 00:57:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1760687840; x=1761292640; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=YeonnmR22YpdBnRA2e84Q5k99IvmMWnT+8o9upY5Y8U=; b=vVDFZY74BUn7SwR+HcQh6hCO1CcPD/ge0uBt1oCTtBtsXJOsEaQ73+aVEkOkuBJCX+ dXBWWSMGJHNuVLRk8PBekaN7dgLC7asULPOlUPz0xR4jZMhyI8nx1Vbfpk++GzdeSnBt 9lkyXcd9CgfE7RpACmj2CPKikse6SOBWudwQLoNCINaowcZQpceES1ik6BmSJ3i5uDIk KUq3Tn5L3BPmTBZCwCZENGnxC30CBd2voS2xbFXheUbOLfzRiC/XDQFQ0NegJIHdkbwo racm6skY8qS+x4TN5P7EYxqhyZVXAL6elqNJPDQGD1S6R49r1rWmly7ZNX63DBcnBJxa FwQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1760687840; x=1761292640; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=YeonnmR22YpdBnRA2e84Q5k99IvmMWnT+8o9upY5Y8U=; b=eq/GaC3uIsm4wAVnMmuPeDHRltSKqTeu90eNvp5CIjX9cgNdTjRXVhZLH6Dsn2c71s yvBW6Hs8QZQk9HxLTnJ+RSS8LVBPl5CajLs3ASWixeCNnwpAZpSIM+IgZNoBXqJAw2pE aSYBvygUU74k6qQrBBY2yVknHowbv9qK27y1C5rMS4UwcMddvl/H7qwIhiKVhgUwLWH+ zLUREKyVOK/1NB3nPa97JNlPm+0baPdGmTleL200RSehxpLPGPvmJ3C92yJaY4LGPg8H BCRJhHHrcPGs9HJbxm8GT/CRwkjfFQqWTWfQGurDin3wsoVOVthY2u5TgYVpxsmdZ2JA 0JJg== X-Forwarded-Encrypted: i=1; AJvYcCUAD50JNnskGkPAxAHxOpar6TAhxrXqKFMSG42+RBK4vg1IixCDupS2yp8ocgl3fFEzxJZjcFrWD7ep2aA=@vger.kernel.org X-Gm-Message-State: AOJu0Yxa20JAqxNwuFU+yHKsjcgZ2L1cHZIzsBnfX34sjm3kEhqdVUbE 4WWhy6mI9IaGRYmz9zt7SuySRSKD1bjSv+ydYU5gR22Zg0KLWJAgq8/4PtXb4oRb/A3/u971kYc 57Kbf7yg+o09syUxz5BqvLvKdA5vJLA== X-Google-Smtp-Source: AGHT+IFurVwu13hTVgjqFkuyg+jJU8SJ/2HWVhpsWHXh/EE63aqE9d17vw6ppnqZ4TszNyVb3fhURmcJUleEuWeLYDE= X-Received: from edya15.prod.google.com ([2002:aa7:cf0f:0:b0:639:f07d:725a]) (user=sebastianene job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:20c2:20b0:63b:f93a:57b with SMTP id 4fb4d7f45d1cf-63c1f6b50c1mr2138541a12.20.1760687839997; Fri, 17 Oct 2025 00:57:19 -0700 (PDT) Date: Fri, 17 Oct 2025 07:57:10 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.51.0.858.gf9c4a03a3a-goog Message-ID: <20251017075710.2605118-1-sebastianene@google.com> Subject: [PATCH] KVM: arm64: Check the untrusted offset in FF-A memory share From: Sebastian Ene To: maz@kernel.org, oliver.upton@linux.dev, will@kernel.org, catalin.marinas@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, joey.gouly@arm.com Cc: ayrton@google.com, yuzenghui@huawei.com, qperret@google.com, vdonnefort@google.com, kernel-team@android.com, Sebastian Ene Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Verify the offset to prevent OOB access in the hypervisor FF-A buffer in case an untrusted large enough value [U32_MAX - sizeof(struct ffa_composite_mem_region) + 1, U32_MAX] is set from the host kernel. Signed-off-by: Sebastian Ene Acked-by: Will Deacon --- 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 4e16f9b96f63..58b7d0c477d7 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; + u32 offset, nr_ranges, checked_offset; int ret =3D 0; =20 if (addr_mbz || npages_mbz || fraglen > len || @@ -516,7 +516,12 @@ static void __do_ffa_mem_xfer(const u64 func_id, goto out_unlock; } =20 - if (fraglen < offset + sizeof(struct ffa_composite_mem_region)) { + if (check_add_overflow(offset, sizeof(struct ffa_composite_mem_region), &= checked_offset)) { + ret =3D FFA_RET_INVALID_PARAMETERS; + goto out_unlock; + } + + if (fraglen < checked_offset) { ret =3D FFA_RET_INVALID_PARAMETERS; goto out_unlock; } --=20 2.51.0.858.gf9c4a03a3a-goog