On Jul 15, 2020, at 11:14 AM, Chuck Lever chuck.lever@oracle.com wrote:
On Jul 15, 2020, at 11:08 AM, Kai-Heng Feng kai.heng.feng@canonical.com wrote:
On Jul 15, 2020, at 23:02, Chuck Lever chuck.lever@oracle.com wrote:
On Jul 15, 2020, at 10:48 AM, Kai-Heng Feng kai.heng.feng@canonical.com 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!
Another thought: Please ask what encryption type is in use. The kerberos_v1 enctypes might exercise a code path I wasn't able to test.
OK.
v5.4.40 does not have 31c9590ae468 and friends, but the claim is this one crashes?
And v5.4.51 has those three and 89a3c9f5b9f0, which Pierre claims fixes the problem for him; but another commenter says v5.4.51 still crashes.
So we're getting inconsistent problem reports.
Have the testers enable memory debugging : KASAN or SLUB debugging might provide more information. I might have some time later this week to try reproducing on upstream stable, but no guarantees.
-- Chuck Lever