Re: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer overflow

Re: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer overflow

[Pablo Neira Ayuso]

On Sat, Jul 02, 2022 at 07:59:11PM +0200, Hugues ANGUELKOV wrote:
> From d91007a18140e02a1f12c9627058a019fe55b8e6 Mon Sep 17 00:00:00 2001
> From: Arthur Mongodin <amongodin@randorisec.fr>
> Date: Sat, 2 Jul 2022 17:11:48 +0200
> Subject: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer
>  overflow
> 
> The length used for the memcpy in nft_set_elem_init may exceed the bound
> of the allocated object due to a weak check in nft_setelem_parse_data.
> As a user can add an element with a data type NFT_DATA_VERDICT to a set
> with a data type different of NFT_DATA_VERDICT, then the comparison on the
> data type of the element allows to avoid the comparaison on the data length
> This fix forces the length comparison in nft_setelem_parse_data by removing
> the check for NFT_DATA_VERDICT type.

https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702021631.796822-1-pablo@netfilter.org/

Re: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer overflow

[Pablo Neira Ayuso]

On Sat, Jul 02, 2022 at 08:57:14PM +0200, Pablo Neira Ayuso wrote:
> On Sat, Jul 02, 2022 at 07:59:11PM +0200, Hugues ANGUELKOV wrote:
> > From d91007a18140e02a1f12c9627058a019fe55b8e6 Mon Sep 17 00:00:00 2001
> > From: Arthur Mongodin <amongodin@randorisec.fr>
> > Date: Sat, 2 Jul 2022 17:11:48 +0200
> > Subject: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer
> >  overflow
> > 
> > The length used for the memcpy in nft_set_elem_init may exceed the bound
> > of the allocated object due to a weak check in nft_setelem_parse_data.
> > As a user can add an element with a data type NFT_DATA_VERDICT to a set
> > with a data type different of NFT_DATA_VERDICT, then the comparison on the
> > data type of the element allows to avoid the comparaison on the data length
> > This fix forces the length comparison in nft_setelem_parse_data by removing
> > the check for NFT_DATA_VERDICT type.
> 
> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702021631.796822-1-pablo@netfilter.org/

For the record, pull request is already available with pending fixes
for net.

https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702191029.238563-1-pablo@netfilter.org/
https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702191029.238563-2-pablo@netfilter.org/
https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702191029.238563-3-pablo@netfilter.org/

Re: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer overflow

[Hugues ANGUELKOV]

On 7/2/22 21:11, Pablo Neira Ayuso wrote:
> On Sat, Jul 02, 2022 at 08:57:14PM +0200, Pablo Neira Ayuso wrote:
>> On Sat, Jul 02, 2022 at 07:59:11PM +0200, Hugues ANGUELKOV wrote:
>>> From d91007a18140e02a1f12c9627058a019fe55b8e6 Mon Sep 17 00:00:00 2001
>>> From: Arthur Mongodin <amongodin@randorisec.fr>
>>> Date: Sat, 2 Jul 2022 17:11:48 +0200
>>> Subject: [PATCH v1] netfilter: nf_tables: fix nft_set_elem_init heap buffer
>>>  overflow
>>>
>>> The length used for the memcpy in nft_set_elem_init may exceed the bound
>>> of the allocated object due to a weak check in nft_setelem_parse_data.
>>> As a user can add an element with a data type NFT_DATA_VERDICT to a set
>>> with a data type different of NFT_DATA_VERDICT, then the comparison on the
>>> data type of the element allows to avoid the comparaison on the data length
>>> This fix forces the length comparison in nft_setelem_parse_data by removing
>>> the check for NFT_DATA_VERDICT type.
>>
>> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702021631.796822-1-pablo@netfilter.org/
> 
> For the record, pull request is already available with pending fixes
> for net.
> 
> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702191029.238563-1-pablo@netfilter.org/
> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702191029.238563-2-pablo@netfilter.org/
> https://patchwork.ozlabs.org/project/netfilter-devel/patch/20220702191029.238563-3-pablo@netfilter.org/

Arthur Mongodin which has found the vulnerability is currently testing the proposed fixes against his exploit.

He is also the original writer of the previously proposed fixes and should be credited as reporter.

I'm currently waiting for his various test results.