CVE Request: Linux: IB/security: Restrict use of the write() interface'

[Salvatore Bonaccorso <carnil () debian org>]

Hi

Jann Horn reported an issue in the infiniband stack. It has been fixed
in v4.6-rc6 with commit e6bd18f57aad1a2d1ef40e646d03ed0f2515c9e3:

https://git.kernel.org/linus/e6bd18f57aad1a2d1ef40e646d03ed0f2515c9e3

> IB/security: Restrict use of the write() interface
> The drivers/infiniband stack uses write() as a replacement for
> bi-directional ioctl().  This is not safe. There are ways to
> trigger write calls that result in the return structure that
> is normally written to user space being shunted off to user
> specified kernel memory instead.
>
> For the immediate repair, detect and deny suspicious accesses to
> the write API.
>
> For long term, update the user space libraries and the kernel API
> to something that doesn't present the same security vulnerabilities
> (likely a structured ioctl() interface).
>
> The impacted uAPI interfaces are generally only available if
> hardware from drivers/infiniband is installed in the system.

Could you assign a CVE for this issue?

I'm just to avoid possible duplication as well Cc'ing Red Hat's
secalert, since the commit was signed off by Doug Ledford
<dledford () redhat com>.

Regards,
Salvatore