Re: swiotlb/virtio: unchecked device dma address and length

Re: swiotlb/virtio: unchecked device dma address and length

[Konrad Rzeszutek Wilk]

On Fri, Dec 11, 2020 at 06:31:21PM +0100, Felicitas Hetzelt wrote:
> Hello,

Hi! Please see below my responses.

> we have been analyzing the Hypervisor-OS interface of Linux
> and discovered bugs in the swiotlb/virtio implementation that can be
> triggered from a malicious Hypervisor / virtual device.
> With SEV, the SWIOTLB implementation is forcefully enabled and would
> always be used. Thus, all virtio devices and others would use it under
> the hood.
> 
> The reason for analyzing this interface is that, technologies such as
> Intel's Trusted Domain Extensions [1] and AMD's Secure Nested Paging [2]
> change the threat model assumed by various Linux kernel subsystems.
> These technologies take the presence of a fully malicious hypervisor
> into account and aim to provide protection for virtual machines in such
> an environment. Therefore, all input received from the hypervisor or an
> external device should be carefully validated. Note that these issues
> are of little (or no) relevance in a "normal" virtualization setup,
> nevertheless we believe that it is required to fix them if TDX or SNP is
> used.
> 
> We are happy to provide more information if needed!
> 
> [1]
> https://software.intel.com/content/www/us/en/develop/articles/intel-trust-domain-extensions.html
> 
> [2] https://www.amd.com/en/processors/amd-secure-encrypted-virtualization
> 
> Bug:
> OOB memory write.
> dma_unmap_single -> swiotlb_tbl_unmap_single is invoked with dma_addr
> and length parameters that are under control of the device.
> This happens e.g. in virtio_ring:
> https://elixir.bootlin.com/linux/v5.10-rc7/source/drivers/virtio/virtio_ring.c#L378

Heya!

Thank you for pointing this out! I've a couple of questions and hope you can
help me out with them.

Also CC-ing AMD / TDX folks.
> 
> This raises two issues:
> 1) swiotlb_tlb_unmap_single fails to check whether the index generated
> from the dma_addr is in range of the io_tlb_orig_addr array.

That is fairly simple to implement I would think. That is it can check
that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
is used.

> 2) when swiotlb_bounce is called the device controls the length of the
> memory copied to the cpu address.

So.. this sounds very similar to the Intel Thunder.. something issue
where this exact issue was fixed by handing the DMA off to the SWIOTLB
bounce code.

But if that is broken, then that CVE is still not fixed?

So the issue here is that swiotlb_tbl_unmap_single(..,mapping_size,) is
under the attacker control. Ugh.

One way could be to have a io_tlb_orig_addr-ish array with the length
of mappings to double check?

Couple more questions:
 - Did you have already some PoC fixes for this? 
 - Is there a CVE associated with this?
 - Is there a paper on this you all are working on?

Thank you!
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Re: swiotlb/virtio: unchecked device dma address and length

[Jason Wang]

On 2020/12/15 上午5:49, Konrad Rzeszutek Wilk wrote:
> On Fri, Dec 11, 2020 at 06:31:21PM +0100, Felicitas Hetzelt wrote:
>> Hello,
> Hi! Please see below my responses.
>
>> we have been analyzing the Hypervisor-OS interface of Linux
>> and discovered bugs in the swiotlb/virtio implementation that can be
>> triggered from a malicious Hypervisor / virtual device.
>> With SEV, the SWIOTLB implementation is forcefully enabled and would
>> always be used. Thus, all virtio devices and others would use it under
>> the hood.
>>
>> The reason for analyzing this interface is that, technologies such as
>> Intel's Trusted Domain Extensions [1] and AMD's Secure Nested Paging [2]
>> change the threat model assumed by various Linux kernel subsystems.
>> These technologies take the presence of a fully malicious hypervisor
>> into account and aim to provide protection for virtual machines in such
>> an environment. Therefore, all input received from the hypervisor or an
>> external device should be carefully validated. Note that these issues
>> are of little (or no) relevance in a "normal" virtualization setup,
>> nevertheless we believe that it is required to fix them if TDX or SNP is
>> used.
>>
>> We are happy to provide more information if needed!
>>
>> [1]
>> https://software.intel.com/content/www/us/en/develop/articles/intel-trust-domain-extensions.html
>>
>> [2]https://www.amd.com/en/processors/amd-secure-encrypted-virtualization
>>
>> Bug:
>> OOB memory write.
>> dma_unmap_single -> swiotlb_tbl_unmap_single is invoked with dma_addr
>> and length parameters that are under control of the device.
>> This happens e.g. in virtio_ring:
>> https://elixir.bootlin.com/linux/v5.10-rc7/source/drivers/virtio/virtio_ring.c#L378
> Heya!
>
> Thank you for pointing this out! I've a couple of questions and hope you can
> help me out with them.
>
> Also CC-ing AMD / TDX folks.
>> This raises two issues:
>> 1) swiotlb_tlb_unmap_single fails to check whether the index generated
>> from the dma_addr is in range of the io_tlb_orig_addr array.
> That is fairly simple to implement I would think. That is it can check
> that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
> is used.


I'm not sure this can fix all the cases. It looks to me we should map 
descriptor coherent but readonly (which is not supported by current DMA 
API).

Otherwise, device can modify the desc[i].addr/desc[i].len at any time to 
pretend a valid mapping.

Thanks


>

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Re: swiotlb/virtio: unchecked device dma address and length

[Konrad Rzeszutek Wilk]

.snip.
> > > This raises two issues:
> > > 1) swiotlb_tlb_unmap_single fails to check whether the index generated
> > > from the dma_addr is in range of the io_tlb_orig_addr array.
> > That is fairly simple to implement I would think. That is it can check
> > that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
> > is used.
> 
> 
> I'm not sure this can fix all the cases. It looks to me we should map
> descriptor coherent but readonly (which is not supported by current DMA
> API).

I think I am missing something obvious here. The attacker is the hypervisor, aka
the owner of the VirtIO device (ring0). The attacker is the one that
provides the addr/len - having that readonly from a guest perspective
does not change the fact that the hypervisor can modify the memory range
by mapping it via a different virtual address in the hypervisor? (aka
aliasing it).
> 
> Otherwise, device can modify the desc[i].addr/desc[i].len at any time to
> pretend a valid mapping.

With the swiotlb=force as long as addr/len are within the PA boundaries
within the SWIOTLB pool this should be OK?

After all that whole area is in cleartext and visible to the attacker.
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Re: swiotlb/virtio: unchecked device dma address and length

[Jason Wang]

----- Original Message -----
> .snip.
> > > > This raises two issues:
> > > > 1) swiotlb_tlb_unmap_single fails to check whether the index generated
> > > > from the dma_addr is in range of the io_tlb_orig_addr array.
> > > That is fairly simple to implement I would think. That is it can check
> > > that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
> > > is used.
> > 
> > 
> > I'm not sure this can fix all the cases. It looks to me we should map
> > descriptor coherent but readonly (which is not supported by current DMA
> > API).
> 
> I think I am missing something obvious here. The attacker is the hypervisor,
> aka
> the owner of the VirtIO device (ring0). The attacker is the one that
> provides the addr/len - having that readonly from a guest perspective
> does not change the fact that the hypervisor can modify the memory range
> by mapping it via a different virtual address in the hypervisor? (aka
> aliasing it).

Right, but if we allow hypervisor to provide arbitrary addr/len, does
it mean hypervisor can read uncrypted content of encrypted memory of
guest through swiotlb?

Thanks

> > 
> > Otherwise, device can modify the desc[i].addr/desc[i].len at any time to
> > pretend a valid mapping.
> 
> With the swiotlb=force as long as addr/len are within the PA boundaries
> within the SWIOTLB pool this should be OK?
> 
> After all that whole area is in cleartext and visible to the attacker.
> 
> 

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Re: swiotlb/virtio: unchecked device dma address and length

[Jason Wang]

----- Original Message -----
> 
> 
> ----- Original Message -----
> > .snip.
> > > > > This raises two issues:
> > > > > 1) swiotlb_tlb_unmap_single fails to check whether the index
> > > > > generated
> > > > > from the dma_addr is in range of the io_tlb_orig_addr array.
> > > > That is fairly simple to implement I would think. That is it can check
> > > > that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
> > > > is used.
> > > 
> > > 
> > > I'm not sure this can fix all the cases. It looks to me we should map
> > > descriptor coherent but readonly (which is not supported by current DMA
> > > API).
> > 
> > I think I am missing something obvious here. The attacker is the
> > hypervisor,
> > aka
> > the owner of the VirtIO device (ring0). The attacker is the one that
> > provides the addr/len - having that readonly from a guest perspective
> > does not change the fact that the hypervisor can modify the memory range
> > by mapping it via a different virtual address in the hypervisor? (aka
> > aliasing it).
> 
> Right, but if we allow hypervisor to provide arbitrary addr/len, does
> it mean hypervisor can read encrypted content of encrypted memory of
> guest through swiotlb?
> 
> Thanks

Actually not. I think you're right.

Thanks

> 
> > > 
> > > Otherwise, device can modify the desc[i].addr/desc[i].len at any time to
> > > pretend a valid mapping.
> > 
> > With the swiotlb=force as long as addr/len are within the PA boundaries
> > within the SWIOTLB pool this should be OK?
> > 
> > After all that whole area is in cleartext and visible to the attacker.
> > 
> > 
> 

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Re: swiotlb/virtio: unchecked device dma address and length

[Konrad Rzeszutek Wilk]

On December 16, 2020 1:41:48 AM EST, Jason Wang <jasowang@redhat.com> wrote:
>
>
>----- Original Message -----
>> 
>> 
>> ----- Original Message -----
>> > .snip.
>> > > > > This raises two issues:
>> > > > > 1) swiotlb_tlb_unmap_single fails to check whether the index
>> > > > > generated
>> > > > > from the dma_addr is in range of the io_tlb_orig_addr array.
>> > > > That is fairly simple to implement I would think. That is it
>can check
>> > > > that the dma_addr is from the PA in the io_tlb pool when
>SWIOTLB=force
>> > > > is used.
>> > > 
>> > > 
>> > > I'm not sure this can fix all the cases. It looks to me we should
>map
>> > > descriptor coherent but readonly (which is not supported by
>current DMA
>> > > API).
>> > 
>> > I think I am missing something obvious here. The attacker is the
>> > hypervisor,
>> > aka
>> > the owner of the VirtIO device (ring0). The attacker is the one
>that
>> > provides the addr/len - having that readonly from a guest
>perspective
>> > does not change the fact that the hypervisor can modify the memory
>range
>> > by mapping it via a different virtual address in the hypervisor?
>(aka
>> > aliasing it).
>> 
>> Right, but if we allow hypervisor to provide arbitrary addr/len, does
>> it mean hypervisor can read encrypted content of encrypted memory of
>> guest through swiotlb?

Yes .
>> 
>> Thanks
>
>Actually not. I think you're right.


Your sentence is very confusing.

On a DMA unmap SWIOTLB (when force is used) it trusts the driver from providing the correct DMA address and length which SWIOTLB uses to match to its associated original PA address.

Think original PA having a mapping to a PA in the SWIOTLB pool.


The length is not checked so the attacker can modify that to say a huge number and cause SWIOTLB bounce code to write or read data from non SWIOTLB PA into the SWIOTLB PA pool.




>
>Thanks
>
>> 
>> > > 
>> > > Otherwise, device can modify the desc[i].addr/desc[i].len at any
>time to
>> > > pretend a valid mapping.
>> > 
>> > With the swiotlb=force as long as addr/len are within the PA
>boundaries
>> > within the SWIOTLB pool this should be OK?
>> > 
>> > After all that whole area is in cleartext and visible to the
>attacker.
>> > 
>> > 
>> 

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Re: swiotlb/virtio: unchecked device dma address and length

[Jason Wang]

On 2020/12/16 下午9:04, Konrad Rzeszutek Wilk wrote:
> On December 16, 2020 1:41:48 AM EST, Jason Wang <jasowang@redhat.com> wrote:
>>
>> ----- Original Message -----
>>>
>>> ----- Original Message -----
>>>> .snip.
>>>>>>> This raises two issues:
>>>>>>> 1) swiotlb_tlb_unmap_single fails to check whether the index
>>>>>>> generated
>>>>>>> from the dma_addr is in range of the io_tlb_orig_addr array.
>>>>>> That is fairly simple to implement I would think. That is it
>> can check
>>>>>> that the dma_addr is from the PA in the io_tlb pool when
>> SWIOTLB=force
>>>>>> is used.
>>>>>
>>>>> I'm not sure this can fix all the cases. It looks to me we should
>> map
>>>>> descriptor coherent but readonly (which is not supported by
>> current DMA
>>>>> API).
>>>> I think I am missing something obvious here. The attacker is the
>>>> hypervisor,
>>>> aka
>>>> the owner of the VirtIO device (ring0). The attacker is the one
>> that
>>>> provides the addr/len - having that readonly from a guest
>> perspective
>>>> does not change the fact that the hypervisor can modify the memory
>> range
>>>> by mapping it via a different virtual address in the hypervisor?
>> (aka
>>>> aliasing it).
>>> Right, but if we allow hypervisor to provide arbitrary addr/len, does
>>> it mean hypervisor can read encrypted content of encrypted memory of
>>> guest through swiotlb?
> Yes .
>>> Thanks
>> Actually not. I think you're right.
>
> Your sentence is very confusing.


Sorry for  being unclear. This is all a reply to your suggestion of 
adding checks in the swiotlb.


>
> On a DMA unmap SWIOTLB (when force is used) it trusts the driver from providing the correct DMA address and length which SWIOTLB uses to match to its associated original PA address.
>
> Think original PA having a mapping to a PA in the SWIOTLB pool.
>
>
> The length is not checked so the attacker can modify that to say a huge number and cause SWIOTLB bounce code to write or read data from non SWIOTLB PA into the SWIOTLB PA pool.


How can we read in this case? It looks to me we don't try to read during 
dma_unmap().

Thanks


>
>
>
>
>> Thanks
>>
>>>>> Otherwise, device can modify the desc[i].addr/desc[i].len at any
>> time to
>>>>> pretend a valid mapping.
>>>> With the swiotlb=force as long as addr/len are within the PA
>> boundaries
>>>> within the SWIOTLB pool this should be OK?
>>>>
>>>> After all that whole area is in cleartext and visible to the
>> attacker.
>>>>

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Re: swiotlb/virtio: unchecked device dma address and length

[Michael S. Tsirkin]

On Tue, Dec 15, 2020 at 11:20:48AM +0800, Jason Wang wrote:
> 
> On 2020/12/15 上午5:49, Konrad Rzeszutek Wilk wrote:
> > On Fri, Dec 11, 2020 at 06:31:21PM +0100, Felicitas Hetzelt wrote:
> > > Hello,
> > Hi! Please see below my responses.
> > 
> > > we have been analyzing the Hypervisor-OS interface of Linux
> > > and discovered bugs in the swiotlb/virtio implementation that can be
> > > triggered from a malicious Hypervisor / virtual device.
> > > With SEV, the SWIOTLB implementation is forcefully enabled and would
> > > always be used. Thus, all virtio devices and others would use it under
> > > the hood.
> > > 
> > > The reason for analyzing this interface is that, technologies such as
> > > Intel's Trusted Domain Extensions [1] and AMD's Secure Nested Paging [2]
> > > change the threat model assumed by various Linux kernel subsystems.
> > > These technologies take the presence of a fully malicious hypervisor
> > > into account and aim to provide protection for virtual machines in such
> > > an environment. Therefore, all input received from the hypervisor or an
> > > external device should be carefully validated. Note that these issues
> > > are of little (or no) relevance in a "normal" virtualization setup,
> > > nevertheless we believe that it is required to fix them if TDX or SNP is
> > > used.
> > > 
> > > We are happy to provide more information if needed!
> > > 
> > > [1]
> > > https://software.intel.com/content/www/us/en/develop/articles/intel-trust-domain-extensions.html
> > > 
> > > [2]https://www.amd.com/en/processors/amd-secure-encrypted-virtualization
> > > 
> > > Bug:
> > > OOB memory write.
> > > dma_unmap_single -> swiotlb_tbl_unmap_single is invoked with dma_addr
> > > and length parameters that are under control of the device.
> > > This happens e.g. in virtio_ring:
> > > https://elixir.bootlin.com/linux/v5.10-rc7/source/drivers/virtio/virtio_ring.c#L378
> > Heya!
> > 
> > Thank you for pointing this out! I've a couple of questions and hope you can
> > help me out with them.
> > 
> > Also CC-ing AMD / TDX folks.
> > > This raises two issues:
> > > 1) swiotlb_tlb_unmap_single fails to check whether the index generated
> > > from the dma_addr is in range of the io_tlb_orig_addr array.
> > That is fairly simple to implement I would think. That is it can check
> > that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
> > is used.
> 
> 
> I'm not sure this can fix all the cases. It looks to me we should map
> descriptor coherent but readonly (which is not supported by current DMA
> API).

Neither is this supported but encrypted memory technologies.

> Otherwise, device can modify the desc[i].addr/desc[i].len at any time to
> pretend a valid mapping.
> 
> Thanks
> 
> 
> > 

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Re: swiotlb/virtio: unchecked device dma address and length

[Konrad Rzeszutek Wilk]

..snip..
>> > > This raises two issues:
>> > > 1) swiotlb_tlb_unmap_single fails to check whether the index
>generated
>> > > from the dma_addr is in range of the io_tlb_orig_addr array.
>> > That is fairly simple to implement I would think. That is it can
>check
>> > that the dma_addr is from the PA in the io_tlb pool when
>SWIOTLB=force
>> > is used.
>> 
>> 
>> I'm not sure this can fix all the cases. It looks to me we should map
>> descriptor coherent but readonly (which is not supported by current
>DMA
>> API).
>
>Neither is this supported but encrypted memory technologies.


-ECONFUSED.

Could you state this once more please? I am not exactly sure what you are saying 

>
>> Otherwise, device can modify the desc[i].addr/desc[i].len at any time
>to
>> pretend a valid mapping.
>> 
>> Thanks
>> 
>> 
>> > 

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Re: swiotlb/virtio: unchecked device dma address and length

[Konrad Rzeszutek Wilk]

On Tue, Dec 15, 2020 at 11:54:08AM +0100, Felicitas Hetzelt wrote:
> Hello,
> thank you all for looking into this! To answer some of the questions:
>  - Did you have already some PoC fixes for this:
>    We don't have a full PoC or fix currently. Thought we have a PoC
>    with which were able to overwrite memory outside of the mapped
>    dma region.
>  - Is there a CVE associated with this?
>    No
>  - Is there a paper on this you all are working on?
>    Yes, we were planning to use this bug (among others
>    in a paper)
> 
> Could you point us to the intel thunder issue that you mentioned?

ThunderClap was it!

https://lwn.net/Articles/786558/

Cc-ing Lu Baolu ..

Hm, this was a year ago and it looks like there are some extra SWIOTLB
patches to be done ?

> 
> On 12/15/20 9:47 AM, Ashish Kalra wrote:
> > On Mon, Dec 14, 2020 at 04:49:50PM -0500, Konrad Rzeszutek Wilk wrote:
> >> On Fri, Dec 11, 2020 at 06:31:21PM +0100, Felicitas Hetzelt wrote:
> >>> Hello,
> >>
> >> Hi! Please see below my responses.
> >>
> >>> we have been analyzing the Hypervisor-OS interface of Linux
> >>> and discovered bugs in the swiotlb/virtio implementation that can be
> >>> triggered from a malicious Hypervisor / virtual device.
> >>> With SEV, the SWIOTLB implementation is forcefully enabled and would
> >>> always be used. Thus, all virtio devices and others would use it under
> >>> the hood.
> >>>
> >>> The reason for analyzing this interface is that, technologies such as
> >>> Intel's Trusted Domain Extensions [1] and AMD's Secure Nested Paging [2]
> >>> change the threat model assumed by various Linux kernel subsystems.
> >>> These technologies take the presence of a fully malicious hypervisor
> >>> into account and aim to provide protection for virtual machines in such
> >>> an environment. Therefore, all input received from the hypervisor or an
> >>> external device should be carefully validated. Note that these issues
> >>> are of little (or no) relevance in a "normal" virtualization setup,
> >>> nevertheless we believe that it is required to fix them if TDX or SNP is
> >>> used.
> >>>
> >>> We are happy to provide more information if needed!
> >>>
> >>> [1]
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fsoftware.intel.com%2Fcontent%2Fwww%2Fus%2Fen%2Fdevelop%2Farticles%2Fintel-trust-domain-extensions.html&data=04%7C01%7Cashish.kalra%40amd.com%7C1d1cbca182a84c0e504708d8a079eec0%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637435792867090126%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=THAJlYGLSOx3bKQYH62TLKH50By7Wnsu0z92snfNY84%3D&reserved=0
> >>>
> >>> [2] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.amd.com%2Fen%2Fprocessors%2Famd-secure-encrypted-virtualization&data=04%7C01%7Cashish.kalra%40amd.com%7C1d1cbca182a84c0e504708d8a079eec0%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637435792867090126%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=M3jmYCWaEvmAzIy%2F4z5XstsPf812SbEkuNX5PVVr0HY%3D&reserved=0
> >>>
> >>> Bug:
> >>> OOB memory write.
> >>> dma_unmap_single -> swiotlb_tbl_unmap_single is invoked with dma_addr
> >>> and length parameters that are under control of the device.
> >>> This happens e.g. in virtio_ring:
> >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.10-rc7%2Fsource%2Fdrivers%2Fvirtio%2Fvirtio_ring.c%23L378&data=04%7C01%7Cashish.kalra%40amd.com%7C1d1cbca182a84c0e504708d8a079eec0%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637435792867090126%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=j0CIi%2F8hBkVx45XGBtT4Ri52uWIOdOts%2BSbJ0kCB5B0%3D&reserved=0
> >>
> >> Heya!
> >>
> >> Thank you for pointing this out! I've a couple of questions and hope you can
> >> help me out with them.
> >>
> >> Also CC-ing AMD / TDX folks.
> >>>
> > 
> > Adding more relevant folks in AMD.
> > 
> > Needless to say, the swiotlb code needs to validate this external untrusted input dma_addr and length parameters.
> > 
> > Thanks,
> > Ashish
> > 
> >>> This raises two issues:
> >>> 1) swiotlb_tlb_unmap_single fails to check whether the index generated
> >>> from the dma_addr is in range of the io_tlb_orig_addr array.
> >>
> >> That is fairly simple to implement I would think. That is it can check
> >> that the dma_addr is from the PA in the io_tlb pool when SWIOTLB=force
> >> is used.
> >>
> >>> 2) when swiotlb_bounce is called the device controls the length of the
> >>> memory copied to the cpu address.
> >>
> >> So.. this sounds very similar to the Intel Thunder.. something issue
> >> where this exact issue was fixed by handing the DMA off to the SWIOTLB
> >> bounce code.
> >>
> >> But if that is broken, then that CVE is still not fixed?
> >>
> >> So the issue here is that swiotlb_tbl_unmap_single(..,mapping_size,) is
> >> under the attacker control. Ugh.
> >>
> >> One way could be to have a io_tlb_orig_addr-ish array with the length
> >> of mappings to double check?
> >>
> >> Couple more questions:
> >>  - Did you have already some PoC fixes for this? 
> >>  - Is there a CVE associated with this?
> >>  - Is there a paper on this you all are working on?
> >>
> >> Thank you!
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