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

[Kai-Heng Feng]

> On Jul 15, 2020, at 23:02, Chuck Lever <chuck.lever@xxxxxxxxxx> wrote:
> 
> 
> 
>> 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.

Yes, it's included. The commit is part of upstream stable 5.4.

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

I'll ask users to test it out. 
Thanks for you quick reply!

Kai-Heng

> 
> 
> --
> Chuck Lever
> 
> 
>