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Bug 1301581

Summary: Back port of bz 1163891 required as rpc.mountd can be blocked by a bad client
Product: Red Hat Enterprise Linux 6 Reporter: Rinku <rkothiya>
Component: nfs-utilsAssignee: Steve Dickson <steved>
Status: CLOSED ERRATA QA Contact: Yongcheng Yang <yoyang>
Severity: urgent Docs Contact:
Priority: urgent    
Version: 6.7CC: cww, djeffery, dwysocha, eguan, fs-qe, mkolaja, ngalvin, sbhat, steved, yoyang
Target Milestone: rcKeywords: ZStream
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: nfs-utils-1.2.3-71.el6 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of:
: 1350702 (view as bug list) Environment:
Last Closed: 2017-03-21 11:23:11 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1269194, 1350702    

Comment 6 Yongcheng Yang 2016-04-19 02:23:39 UTC
*** Bug 1205573 has been marked as a duplicate of this bug. ***

Comment 11 Dave Wysochanski 2016-06-22 15:28:23 UTC
I'm not sure about a hotfix for this bug.  The first patch header states it is 'experimental'.  Are we sure these 3 patches won't have side-effects?  I have not reviewed the 3 patches carefully in detail.

Might be more appropriate for a Z-stream.  SteveD - what do you think - should these be safe or do we need some QE before releasing?

commit e4569a0961ff9f059b9ae71327d291cf95399597
Author: Bodo Stroesser <bstroesser.com>
Date:   Wed Nov 12 09:43:29 2014 -0500

    rpc.mountd: set libtirpc nonblocking mode to avoid DOS
    
    This patch is experimental. In works fine in that it removes the
    vulnerability against a DOS attack. rpc.mountd can be blocked by
    a bad client, that sends many RPC requests but never reads the
    responses. This might happen intentionally or caused by a wrong
    network config (MTU). The patch switches on the nonblocking
    mode of libtirpc. In that mode writes can block for a max of 2 seconds.
    Attackers are forced to send requests slower, as libtirpc will close
    a connection if it finds two requests to read at the same time.
    
    Reviewed-by: NeilBrown <neilb>
    Signed-off-by: Bodo Stroesser <bstroesser.com>
    Signed-off-by: Steve Dickson <steved>

Comment 12 Steve Dickson 2016-06-27 11:27:54 UTC
(In reply to Dave Wysochanski from comment #11)
> I'm not sure about a hotfix for this bug.  The first patch header states it
> is 'experimental'.  Are we sure these 3 patches won't have side-effects?  I
> have not reviewed the 3 patches carefully in detail.
> 
> Might be more appropriate for a Z-stream.  SteveD - what do you think -
> should these be safe or do we need some QE before releasing?
> 
> commit e4569a0961ff9f059b9ae71327d291cf95399597
> Author: Bodo Stroesser <bstroesser.com>
> Date:   Wed Nov 12 09:43:29 2014 -0500
> 
>     rpc.mountd: set libtirpc nonblocking mode to avoid DOS
>     
Its been in place for a number of years and its in RHEL 7
so I'm thinking the three are fairly stable.

I agree with going through the Z-stream process allowing 
QE to do some testing...

Comment 16 Yongcheng Yang 2016-11-01 07:19:52 UTC
Moving to VERIFIED according to test logs of Comment #15.

Also include this automatic case as regression test in the future.

Comment 18 errata-xmlrpc 2017-03-21 11:23:11 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2017-0741.html