Re: [PATCH v4.4/bluetooth 2/2] Bluetooth: Disconnect if E0 is used for Level 4

[Greg KH]

On Thu, Oct 15, 2020 at 09:43:33AM +0200, Hans-Christian Noren Egtvedt wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> 
> E0 is not allowed with Level 4:
> 
> BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C page 1319:
> 
>   '128-bit equivalent strength for link and encryption keys
>    required using FIPS approved algorithms (E0 not allowed,
>    SAFER+ not allowed, and P-192 not allowed; encryption key
>    not shortened'
> 
> SC enabled:
> 
> > HCI Event: Read Remote Extended Features (0x23) plen 13
>         Status: Success (0x00)
>         Handle: 256
>         Page: 1/2
>         Features: 0x0b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
>           Secure Simple Pairing (Host Support)
>           LE Supported (Host)
>           Secure Connections (Host Support)
> > HCI Event: Encryption Change (0x08) plen 4
>         Status: Success (0x00)
>         Handle: 256
>         Encryption: Enabled with AES-CCM (0x02)
> 
> SC disabled:
> 
> > HCI Event: Read Remote Extended Features (0x23) plen 13
>         Status: Success (0x00)
>         Handle: 256
>         Page: 1/2
>         Features: 0x03 0x00 0x00 0x00 0x00 0x00 0x00 0x00
>           Secure Simple Pairing (Host Support)
>           LE Supported (Host)
> > HCI Event: Encryption Change (0x08) plen 4
>         Status: Success (0x00)
>         Handle: 256
>         Encryption: Enabled with E0 (0x01)
> [May 8 20:23] Bluetooth: hci0: Invalid security: expect AES but E0 was used
> < HCI Command: Disconnect (0x01|0x0006) plen 3
>         Handle: 256
>         Reason: Authentication Failure (0x05)
> 
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> (cherry picked from commit 8746f135bb01872ff412d408ea1aa9ebd328c1f5)
> (cherry picked from commit f263237a1709a6dbf1dc9945187f1e64c53a4b73)

I do not see this commit in Linus's tree.

> ---
> AFAICT, fixing CVE 2020-10135 Bluetooth impersonation attacks have been
> left out for the 4.4 stable kernel. I cherry picked what I assume are
> the appropriate two patches missing from the 4.9 stable kernel. Please
> add them to upcoming 4.4 stable releases.

Same thing as before, we need this in all kernels.

thanks,

greg k-h