From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f181.google.com (mail-qt1-f181.google.com [209.85.160.181]) (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 35D77275AFD for ; Wed, 13 May 2026 13:53:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778680417; cv=none; b=H3GzKavWNszDoJ7dL9R/hdrZ1tFQkvyPq5WUt+mhmd8UHI6KP1tFqyexjNGFfQpoaEixxoTAPNvnKf6WVZ8t/PCIwqVfQ0cCNEcgPT1xeb1Y+fcHuJcLANPumlA7EGWvVNqyRWCWJKdvlG0q+KaqEcuhrK+mDRqx8y8HC7zDgGc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778680417; c=relaxed/simple; bh=ofdHaHFEMpVkg7dUSVUdr40lziYvJsc5aRLaxKiysAY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ptyUADk4C6TVfxs8hAnuAGPmYMjg3QM78YPBp4Wv1HhVgqtCJ8hlp24W8R+k5jdX6zTowqSb0FxirrI8KAD0bc9bDsRckdcdqKB+UZqTkBDiRLnPiz5wDjk9YiqIot9ZaRKVveE6FkHdvN62qU5NLvcs/O8DblkpFmoVzJMytzY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Qhl8FUA7; arc=none smtp.client-ip=209.85.160.181 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=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Qhl8FUA7" Received: by mail-qt1-f181.google.com with SMTP id d75a77b69052e-515548f390fso3701cf.0 for ; Wed, 13 May 2026 06:53:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778680415; x=1779285215; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=8J6GRvshR84cVDL8+yqDVLhfMFpXsrxiE9ecLJtpmYg=; b=Qhl8FUA7UJLlr8cOeR1l0i1n7aj83lAYkzUv2ln6HwuPQ3kaHpNj/L5fCnECi2gF3c ZSbsvfd26463RonqcHABtaa5d5wsB7H6mGF7XeyhxkODpFeleMs0XAFVoLdiYHJzZd8n sj2xQ+yxNes1IH0bjyGsOvcjph1g2KKRLfId75oCFKt/3+9iLuOd8on1tFBt4ZlfI4WE m8PBijH2u1CPKgdfS8deutXkVTb+sptLAMDBoXGd8R6VOurTURouK/WZuF/09/URC3LY rHplVgxihuTwSHla6DduUIMBnF1lIPYHS5a59yvNg9/0wECk3Ld0LefCfACqzfFAQAV9 ASfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778680415; x=1779285215; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=8J6GRvshR84cVDL8+yqDVLhfMFpXsrxiE9ecLJtpmYg=; b=iex+f85ARbOxNj07pNIzJaznr7hFFopfaqsF5r1ijUd+KUm0PNUG9xIp9X6UccfQpm fkUZOGVjSCTpzQPLFyvwErMguGVcXGDn0PBsm2OA8gX0MFUShS1l7Z0c5r9QNBnge+Rd N1d4Q8jXisu/5VuR4ewwiMkeuCahZnto/Ot45OetoWisv/hsReDc1sMypNzQ/tjUbQyr v/OCmpPGe16zjFkduJKp6IJNfM5+W9wWIFv8qUAc4OrWcI115Od3cewjVvII1pjNsYgQ VGcnia4shFfgovRj1YlmcA2rOhkX9FnU7shPKln1rg3wcLlmb22AEnMiv0nnLOfuvOfr BdPA== X-Forwarded-Encrypted: i=1; AFNElJ+SSNNlszHUDcsG3z6NFy8H01Jls3vMb0iNTPpDCD3gSFxSh0eqPbubLlVS92OWrdy6t/XpmFnPWAJ4LDY=@vger.kernel.org X-Gm-Message-State: AOJu0YyNSvRLUPVLYMnhKOzVrbjEjAXuov5j8Okybi+7p64tPEDI3ofw DRvvbcIkWafbEgsfi0kuQ/DXXgsvboZ9nPvV/MplxiZRS4fLRkbCyA2arR6D5oyD5g== X-Gm-Gg: Acq92OGdmSLpJ2YRcwX0TsyGb9dGcTJDGyLU9yEJD5FvwzfqVYiORCWMEbQ8LX8JDeM bAe1/eq/WN/yRodIS2/NjO/TCXzsKWwP/Cn+1Qj9lxECuzbxKfgGLAoWoWzb9GJ2YTABtfc3goD 7apii0vc6PUhGi9ueIrdhwJGjBZNS75D24dk8G/cfCGEvKLp41DNJjTFV9+dn9rpSJ8JdJh7Bal eC5DouS957hTGo5HnUX/k358BnT9CWPRYLFJ3+z/qXttfFbRxMf0mGI5knd0S/kJqEsU8lLKyZg D5xmcb4fX5eriBvbZXQtTj4NLr5TlwHH4YjvSfYMURwnaIg2XIpSiAeWfQe70z2WIkP6uzHbJ1t QnUQvPAjiuFtMPyXQEwtV7BMIO1gxDuQkNirSpa913QhV7YTKLqWgP7qmNoDDmY5td2i0VGREDA 95rjFdNvTYXKbFsshUflyoV7SuDr51Rtm4Kv1yV5Ik57kZFw08s9VUr8HAPLqOL1B4L60HSYU7J Y2uQns= X-Received: by 2002:ac8:5c86:0:b0:510:fa1:73c5 with SMTP id d75a77b69052e-5162b16988amr18374031cf.16.1778680414453; Wed, 13 May 2026 06:53:34 -0700 (PDT) Received: from google.com (8.181.38.34.bc.googleusercontent.com. [34.38.181.8]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-65db6dd6ca8sm6202887d50.4.2026.05.13.06.53.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 May 2026 06:53:33 -0700 (PDT) Date: Wed, 13 May 2026 13:53:24 +0000 From: Mostafa Saleh To: Sebastian Ene Cc: catalin.marinas@arm.com, maz@kernel.org, oupton@kernel.org, sudeep.holla@kernel.org, will@kernel.org, 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, suzuki.poulose@arm.com, vdonnefort@google.com, yuzenghui@huawei.com Subject: Re: [PATCH v3 2/2] KVM: arm64: Validate the offset to the mem access descriptor Message-ID: References: <20260512124442.1899107-1-sebastianene@google.com> <20260512124442.1899107-3-sebastianene@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260512124442.1899107-3-sebastianene@google.com> On Tue, May 12, 2026 at 12:44:42PM +0000, Sebastian Ene wrote: > 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 Reviewed-by: Mostafa Saleh Thanks, Mostafa > --- > 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 >