[LU-11414] 'read on open' breaks GSS integrity check

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.12.0
• Fix Version/s: Lustre 2.12.0
• Type: Bug
• Priority: Critical
• Reporter: Sebastien Buisson
• Assignee: Mikhail Pershin
• Resolution: Fixed
• Labels: DoM2, gss
• Severity: 3

Description

Feature 'read on open for DoM files' breaks GSS integrity check.

Indeed, when ski or krb5i flavors are selected, GSS integrity mechanism signs requests on client side before they are sent, and then checks signature on server side upon receiving.
So it is not possible to alter the request content once signature is calculated.

However, with the patch implementing 'read on open for DoM files' (https://review.whamcloud.com/23011), the value of request->rq_reqmsg->lm_repsize is changed after the request has been wrapped. And this field is included in request->rq_reqbuf on which the signature is calculated.
So the signature calculated on the received request on server side does not match the signature calculated on client side.

Consequence is that it is not possible to use Kerberos or Shared Key with integrity protection flavors (and possible full encryption flavors as well).

Comments

[Joseph Gmitter (Inactive)]

Hi Mike,

Can you please take a look at this?

Thanks.

Joe

[Mikhail Pershin]

Sebastien, what is the simple way to check that problem?

[Sebastien Buisson]

Hi Mike,

You can try to run sanity-gss test_1 with SHARED_KEYS=true. Even the fact that preparation before test_1 succeeds would be a good sign.
But it may fail for an unrelated reason. I can test a patch for you if you want.

Thanks,
Sebastien.

[Gerrit Updater]

Mike Pershin ([e-mail]) uploaded a new patch: https://review.whamcloud.com/33223
Subject: LU-11414 ptlrpc: don't change buffer when signature is ready
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 7b6683cc5608d7698bf2869601fb13e66b80ca4a

[Mikhail Pershin]

Sebastien, I think this patch should restore GSS functionality. I would appreciate help with testing it, thanks.

[Sebastien Buisson]

Mike, just tested patch at https://review.whamcloud.com/33223 , it fixes GSS regression, thanks.

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/33223/
Subject: LU-11414 ptlrpc: don't change buffer when signature is ready
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: cf503e047c7fe58c3f75c912b3ce8da93f79bf0e

[Peter Jones]

Landed for 2.12