Re: Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()

Re: Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()

[Red Hat Product Security]

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Hello!

INC2885107 (Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()) has been updated.

Opened for: rfrohl@suse.de
Followers: cve@kernel.org, linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, security@suse.de

Rohit Keshri updated your request with the following comments:

Hello Robert,
 Thank you for reaching to Red Hat Product Security.
 I have reviewed the flaws, CVE-2023-1192 has the correct patch used in the reference.
 Also, CVE-2023-52572 is a duplicate of CVE-2023-1192, which we will soon request for the same.
 I will also share some observation for CVE-2023-1192 while it us under investigation:
~~~
## TL;DR
 After CIFS transfers response data to system call, there is still a local variable points to the memory region, and if system call frees it faster than CIFS uses it, CIFS will access a free memory region when calls function such as `smb2_is_status_io_timeout()` .
 ## Detail
 When client uses CIFS, system calls about file operation will call cifs API to send samba request, and there is a CIFS kernel thread handler `cifs_demultiplex_thread()` which receives response from remote server and transfer those data to corresponding syscall request.
 In the beginning, CIFS kernel thread will allocate memory chunk to `server->smallbuf` in function `allocate_buffers()` and assign the pointer to local variable `buf` . Then cifs kernel thread will get a `struct mid_q_entry` instance from `server->ops->find_mid()` , this struct is used to transfer data between kernel thread and system call. Then cifs kernel thread calls `standard_receive3()` to receive response from server, saving data into `server->smallbuf`, assigning `server->smallbuf` to `mid_q_entry` instance `mids[0]`, and marking this `mid_q_entry` has been received response finally.
~~~
 Please let us know if there are any further queries on this please.
 Regards,
Rohit

How can I track and update my request?

To respond, reply to this email. You may also create a new email and include the request number (INC2885107) in the subject.

Thank you,
Product Security

Ref:MSG86263708

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Re: Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()

[Greg KH]

On Tue, Mar 05, 2024 at 10:30:08AM -0800, Red Hat Product Security wrote:
> 
> Hello Robert,
>  Thank you for reaching to Red Hat Product Security.
>  I have reviewed the flaws, CVE-2023-1192 has the correct patch used in the reference.

What do you mean by "reference"?

CVE-2023-1192 points to a patch for a totally different filesystem
(ntfs3).  Will that be fixed?

And please stop responding in HTML format, the mailing lists reject this :(

thanks,

greg k-h

Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()

[Robert Frohl]

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On 06.03.24 10:16, Greg KH wrote:
> On Tue, Mar 05, 2024 at 10:30:08AM -0800, Red Hat Product Security wrote:
>>
>> Hello Robert,
>>   Thank you for reaching to Red Hat Product Security.
>>   I have reviewed the flaws, CVE-2023-1192 has the correct patch used in the reference.
> 
> What do you mean by "reference"?
> 
> CVE-2023-1192 points to a patch for a totally different filesystem
> (ntfs3).  Will that be fixed?

This is also stated in the RH bugzilla, that the initial patch was wrong:
https://bugzilla.redhat.com/show_bug.cgi?id=2154178#c28

> 
> And please stop responding in HTML format, the mailing lists reject this :(
> 
> thanks,
> 
> greg k-h



-- 
Security Engineer, SUSE Software Solutions Germany GmbH, Frankenstraße 
146, 90461 Nürnberg, Germany, GF: Ivo Totev, Andrew McDonald, Werner 
Knoblich (HRB 36809, AG Nürnberg)
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Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()

[Greg KH]

On Wed, Mar 06, 2024 at 10:23:37AM +0100, Robert Frohl wrote:
> On 06.03.24 10:16, Greg KH wrote:
> > On Tue, Mar 05, 2024 at 10:30:08AM -0800, Red Hat Product Security wrote:
> > > 
> > > Hello Robert,
> > >   Thank you for reaching to Red Hat Product Security.
> > >   I have reviewed the flaws, CVE-2023-1192 has the correct patch used in the reference.
> > 
> > What do you mean by "reference"?
> > 
> > CVE-2023-1192 points to a patch for a totally different filesystem
> > (ntfs3).  Will that be fixed?
> 
> This is also stated in the RH bugzilla, that the initial patch was wrong:
> https://bugzilla.redhat.com/show_bug.cgi?id=2154178#c28

Ok, so what will RH be doing here?

confused,

greg k-h

Re: CVE-2023-52572: cifs: Fix UAF in cifs_demultiplex_thread()

[Robert Frohl]

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On 06.03.24 10:45, Greg KH wrote:
> On Wed, Mar 06, 2024 at 10:23:37AM +0100, Robert Frohl wrote:
>> On 06.03.24 10:16, Greg KH wrote:
>>> On Tue, Mar 05, 2024 at 10:30:08AM -0800, Red Hat Product Security wrote:
>>>>
>>>> Hello Robert,
>>>>    Thank you for reaching to Red Hat Product Security.
>>>>    I have reviewed the flaws, CVE-2023-1192 has the correct patch used in the reference.
>>>
>>> What do you mean by "reference"?
>>>
>>> CVE-2023-1192 points to a patch for a totally different filesystem
>>> (ntfs3).  Will that be fixed?
>>
>> This is also stated in the RH bugzilla, that the initial patch was wrong:
>> https://bugzilla.redhat.com/show_bug.cgi?id=2154178#c28
> 
> Ok, so what will RH be doing here?
> 
> confused,

I hope that the additional information will help to update the published 
information.

The bug states that the initial patch was wrong, but it looks like it 
just was never updated/fixed in the published information for CVE-2023-1192.

Cheers,
Robert

-- 
Security Engineer, SUSE Software Solutions Germany GmbH, Frankenstraße 
146, 90461 Nürnberg, Germany, GF: Ivo Totev, Andrew McDonald, Werner 
Knoblich (HRB 36809, AG Nürnberg)
GPG: D29F 82AA 9FD5 9D6E 74B1  6370 089E DB3D 230A 2404

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