From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ECBE93CDBC0 for ; Wed, 24 Jun 2026 19:53:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782330829; cv=none; b=g5iIia0+NZ4HSZxnVh6eay1qBTS3ZSHfWIl1U8CntGJDizeEdHwq51WTsz+l0fARHzaepQihstJwkyAF8YnX6xQ+3f9BjJQNJ/nEUFimZJAhWZC/P+LPq7wyHtPksZek0qTHonphr6hK8CzLuWyAUQauf7LUsLr+5hwzab3ncIM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782330829; c=relaxed/simple; bh=0sw9vdmmHIrg289S7LBhBP3TAeh5HlhPIfC0XvwKSeg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NeA+dWoFuXKamVRuU3h1cEryUDDW6lMz4zp7DDS0seESHIt6feh4pA83vcqVXe5O/ULvjNWwyd48wQ75d9ZCXbsLb0Ob9f/wiTAfYkEBT1dBU+m+PthLR0S/6tlg4OX0fv3nnX5LGwRmazMF4F3zLTezm4Cxm0ZNIViqBSk0uR4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=OZjT31w4; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=swPeArCF; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="OZjT31w4"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="swPeArCF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782330827; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hQwXPDQFNRwXTCwtbeb7bS0lb7BdO0SS5von3s4mxo4=; b=OZjT31w4T3Df9mAnHts2uNCc8bpuSSl+fa91lrXjNDaQEf3ygGjRjO0tiXGgjNhvJRWoaU rm2T+ERxQMHe3WoLI4fGKkjX6AU6CPOlEM7MKMySP240FPOg9fMlia8Sa3TJmFFSh69TmV SHsdRkUu1efdq5FBhdp8gGltGQOcoh8= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-607-ilIiAPJjOEaCa9q8WJN3nQ-1; Wed, 24 Jun 2026 15:53:44 -0400 X-MC-Unique: ilIiAPJjOEaCa9q8WJN3nQ-1 X-Mimecast-MFC-AGG-ID: ilIiAPJjOEaCa9q8WJN3nQ_1782330823 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-490a060eb84so9015205e9.0 for ; Wed, 24 Jun 2026 12:53:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1782330823; x=1782935623; 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=hQwXPDQFNRwXTCwtbeb7bS0lb7BdO0SS5von3s4mxo4=; b=swPeArCF1ipP67Vhjm78dHJ970rMBZ00ss9gJc1WKGlq5puf4NXjOqoPkHLB83YXLK vRtIHq0X3w1xngyrq6fRW78+AG1y+V7X2m7s4Jw0e8PMnYwA5ccU66wzziJVV4KyLCYT iZYxwZpUkVrvd/koVWHs7CAaZBFsPNRXAafDiF/tcEZF24zSV+eGADhi8eGm8fjgXW9L OHfa2E/rbmcUu0EySMu6AOdWwV1DQI8+Sl+XFpBXi6gSlnK4pd2Vhf6EsRbDdMXFoIwR oHQVdeHLHTxeX49D6ZvXIwl6W8bJ2JCX3Jg/LxtraEO386fWmKRWLPyWDYBNWsc3mKdU K8Yw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782330823; x=1782935623; 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=hQwXPDQFNRwXTCwtbeb7bS0lb7BdO0SS5von3s4mxo4=; b=HlL2a9t+4ZDCk9/9z5o7MjeSqu/sLgfzTol0/++drnVtJ/W0C5APi3rIqknb0/Lyel pSR1rmdt2VkrmzjFk854rMyjXJjTBzucyBr1EYSX/nPgkPX8K16YJRTXyLliVvteypvY UsE2MC0sHphXALoHfdMAsXxuy1ab0MlB3AfvzkRy7iLKymdKtgVF+FWRx4KwU8ipXR4O /D3VQikIUD4dRY7AOJY3Yx3/Nw/qwSwHf2vG0lwbawUg1nhAMNGc2LkZbHUyiUzpgmq2 a1kRTFVsdJCGiVDg3kznSnAhjp0XPZozs4thS8grgV/pkPYcRUDEMaUgzaxpxGxpwJhY EUJQ== X-Forwarded-Encrypted: i=1; AFNElJ+Tj0aT8KPQbFz3/3Lktgso/WnVziujAC5DlLbXicpb2a38PLkfEIrs/saZ9CbcNk3hXtqDhJI=@vger.kernel.org X-Gm-Message-State: AOJu0YzDA6yPt8FVgwrG/dvy73PNNNF1xW04MPu2e8uGU7yDkl0okchJ +V2yAsgcHx4aWCxlqx3Ijz8NyynIjpVk/aVEXcXdnQ7a+hocnei73qhosLiSfc4NtEhQddwPz/r YtvGYOlsoHX0YSa7N6mIT2MymU+VakU/EOkPrunwAoG3HOSQf8bf8qsVib/buBkiLig== X-Gm-Gg: AfdE7ckSO8mCneG3MQpopjz2eghwMCJ7+jWuCNKoV4uyOelZ8ADibF6vAzRk+CAQ888 GKHLnQfXIM52MLpG4QmfnbsZ0IT43Xah5dturKUZTvz4rtqFfB5T2jsGNFUwD6CFfKq/55wE/iY pYVmUGwC1Q+Tpnf7DcJsRET1U21ZbtVPdaXJzryDS2pXjByVpP130wJLD6cc+IsoTjU9S67kVzw miQWC7cm0YHzMTDnWE99LWoKaV2Q7APL7Nsyuc5cZl2CCCz4DATMU4xQfyXMF0/0MHR7RJb3f9P qISF5bkWMPGEGabnwZtDwHLNKQbsfyuzMoFWglm+wDzBnc0jzrpUcCV8L7HgAQqgwjuew70m0y2 lGoC/sl3OVIUTo7pYD2YQ7niFlaEyosV9 X-Received: by 2002:a05:600c:8716:b0:490:e196:eaee with SMTP id 5b1f17b1804b1-4925b359af6mr134949985e9.10.1782330822570; Wed, 24 Jun 2026 12:53:42 -0700 (PDT) X-Received: by 2002:a05:600c:8716:b0:490:e196:eaee with SMTP id 5b1f17b1804b1-4925b359af6mr134949745e9.10.1782330822030; Wed, 24 Jun 2026 12:53:42 -0700 (PDT) Received: from redhat.com (IGLD-80-230-85-71.inter.net.il. [80.230.85.71]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-49264011d5fsm16636315e9.1.2026.06.24.12.53.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jun 2026 12:53:41 -0700 (PDT) Date: Wed, 24 Jun 2026 15:53:38 -0400 From: "Michael S. Tsirkin" To: Yousef Alhouseen Cc: Jason Wang , Eugenio =?iso-8859-1?Q?P=E9rez?= , kvm@vger.kernel.org, virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] vhost/vdpa: reject overflowing PA map page counts Message-ID: <20260624153850-mutt-send-email-mst@kernel.org> References: <20260624190653.2893-1-alhouseenyousef@gmail.com> Precedence: bulk X-Mailing-List: netdev@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: <20260624190653.2893-1-alhouseenyousef@gmail.com> On Wed, Jun 24, 2026 at 09:06:53PM +0200, Yousef Alhouseen wrote: > vhost_vdpa_pa_map() adds the IOVA page offset to the user-controlled map > size before computing the number of pages to pin. If that addition wraps, > the code can pin and map fewer pages than the requested IOTLB range. > > Reject sizes that overflow the page-count calculation. You should add "on 32 bit systems" - I do not see how it can overflow on 64 bit. > Also make the > memlock check subtraction-based so a large page count cannot wrap the > pinned page total. I don't see how this can happen at all - pinned_vm is in units of pages. > Signed-off-by: Yousef Alhouseen > --- > drivers/vhost/vdpa.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index ac55275fa..090cb8693 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -1102,6 +1102,8 @@ static int vhost_vdpa_pa_map(struct vhost_vdpa *v, > unsigned int gup_flags = FOLL_LONGTERM; > unsigned long npages, cur_base, map_pfn, last_pfn = 0; > unsigned long lock_limit, sz2pin, nchunks, i; > + unsigned long page_offset; > + u64 pinned_vm; > u64 start = iova; > long pinned; > int ret = 0; > @@ -1114,7 +1116,12 @@ static int vhost_vdpa_pa_map(struct vhost_vdpa *v, > if (perm & VHOST_ACCESS_WO) > gup_flags |= FOLL_WRITE; > > - npages = PFN_UP(size + (iova & ~PAGE_MASK)); > + page_offset = iova & ~PAGE_MASK; > + if (size > ULONG_MAX - page_offset) { > + ret = -EINVAL; > + goto free; > + } > + npages = PFN_UP(size + page_offset); > if (!npages) { > ret = -EINVAL; > goto free; > @@ -1123,7 +1130,8 @@ static int vhost_vdpa_pa_map(struct vhost_vdpa *v, > mmap_read_lock(dev->mm); > > lock_limit = PFN_DOWN(rlimit(RLIMIT_MEMLOCK)); > - if (npages + atomic64_read(&dev->mm->pinned_vm) > lock_limit) { > + pinned_vm = atomic64_read(&dev->mm->pinned_vm); > + if (npages > lock_limit || pinned_vm > lock_limit - npages) { > ret = -ENOMEM; > goto unlock; > } > -- > 2.54.0