[OpenAFS] Fwd: CRITICAL: RHEL7/CentOS7/SL7 client systems - AuriStorFS v2021.05-10 released > OpenAFS versions?

[Giovanni Bracco]

Are all OpenAFS versions 1.6.x and 1.8.x affected by the bug described 
in the enclosed mail?

Giovanni

-------- Forwarded Message --------
Subject: 	CRITICAL: RHEL7/CentOS7/SL7 client systems - AuriStorFS 
v2021.05-10 released
Date: 	Wed, 10 Nov 2021 12:14:22 -0500
From: 	Jeffrey E Altman <jaltman@auristor.com>
Reply-To: 	info@auristor.com
Organization: 	AuriStor, Inc.
To: 	Giovanni Bracco <giovanni.bracco@enea.it>



Dear community,

This morning AuriStorFS v2010.05-10 was published to workaround a 
CRITICAL kernel bug present in all RHEL7/CentOS7/SL7 releases beginning 
with RHEL 7.5.   All kernels from 3.10.0_861.el7 through 
3.10.0_1160.42.2.el7 are impacted.

The bug was introduced into upstream Linux kernels from 3.2 through 3.15 
by automated patch back-porting tools.  The broken back-port was then 
cherry-picked from the torvalds/linux repository into the rhel7 repository.

RHEL7 is the only Linux distribution for which AuriStor builds kernel 
modules that is impacted by the bug.   AuriStor has submitted to Red Hat 
and Red Hat has accepted a patch which is expected to be included in a 
soon to be released RHEL 7.9 kernel update.

The bug is triggered when the afs disk cache is being read and the 
process that issued the syscall has a pending fatal signal. In this 
case, an EINTR error state results in a file system read failure but the 
file system read returns success.   This bug has minimal impact on a 
userspace process directly issuing a file read because the process will 
be terminated as soon as the syscall completes.  However, the bug can 
corrupt the state of the AuriStorFS cache or the Linux page cache which 
might negatively impact subsequent attempts to perform directory lookups 
or file access.

When this bug is triggered messages similar to those that follow might 
be written to the system message log:

   * yfs: Disk cache read error in CacheItems slot 59151 off
     5205308/19148204 code 0/88
   * yfs: Unexpected directory iteration error (2.822.23.8382
     [your-cell-name.com] @ffffad57888e2424, pos 0, error 22)

Not all code paths impacted by the bug will generate an error. In 
particular, corrupted page cache contents will not log an error.

AuriStor recommends that end users update any RHEL7/CentOS7/SL7 systems 
running AuriStorFS or OpenAFS clients to AuriStorFS v2021.05-10 as soon 
as possible.  AuriStorFS v2021.05-10 contains a workaround for the 
kernel bug.

Please submit any support questions to 
auristorfs-enterprise-support@auristor.com

Sincerely,

Jeffrey Altman
on behalf of the AuriStor team


-- 
Giovanni Bracco
phone  +39 351 8804788
E-mail  giovanni.bracco@enea.it
WWW http://www.afs.enea.it/bracco