Re: [Regression] "SUNRPC: Add "@len" parameter to gss_unwrap()" breaks NFS Kerberos on upstream stable 5.4.y

From: Chuck Lever
Date: Wed Jul 15 2020 - 11:04:12 EST




> On Jul 15, 2020, at 10:48 AM, Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> wrote:
>
> Hi,
>
> Multiple users reported NFS causes NULL pointer dereference [1] on Ubuntu, due to commit "SUNRPC: Add "@len" parameter to gss_unwrap()" and commit "SUNRPC: Fix GSS privacy computation of auth->au_ralign".
>
> The same issue happens on upstream stable 5.4.y branch.
> The mainline kernel doesn't have this issue though.
>
> Should we revert them? Or is there any missing commits need to be backported to v5.4?
>
> [1] https://bugs.launchpad.net/bugs/1886277
>
> Kai-Heng

31c9590ae468 ("SUNRPC: Add "@len" parameter to gss_unwrap()") is a refactoring
change. It shouldn't have introduced any behavior difference. But in theory,
practice and theory should be the same...

Check if 0a8e7b7d0846 ("SUNRPC: Revert 241b1f419f0e ("SUNRPC: Remove xdr_buf_trim()")")
is also applied to 5.4.0-40-generic.

It would help to know if v5.5 stable is working for you. I haven't had any
problems with it.


--
Chuck Lever