Bug 1655681

Summary: rbd_snap_list_end() segfaults if rbd_snap_list() fails
Product: [Red Hat Storage] Red Hat Ceph Storage Reporter: Kefu Chai <kchai>
Component: RBDAssignee: Kefu Chai <kchai>
Status: CLOSED ERRATA QA Contact: Manohar Murthy <mmurthy>
Severity: high Docs Contact: John Brier <jbrier>
Priority: medium    
Version: 3.1CC: anharris, ceph-eng-bugs, edonnell, jdillama, kchai, rperiyas, tchandra, tserlin
Target Milestone: z1   
Target Release: 3.2   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: RHEL: ceph-12.2.8-70.el7cp Ubuntu: ceph_12.2.8-55redhat1 Doc Type: Bug Fix
Doc Text:
.The _python-rbd_ _list_snaps()_ method no longer segfaults after an error This issue was discovered with OpenStack Cinder Backup when `rados_connect_timeout` was set. Normally the timeout is not enabled. If the cluster was highly loaded the timeout could be reached, causing the segfault. With this update to {product}, if the timeout is reached a segfault no longer occurs.
 Story Points: ---
Clone Of:
: 1655685 (view as bug list) Environment:
Last Closed: 2019-03-07 15:51:12 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: 1629656, 1655685    

Description Kefu Chai 2018-12-03 16:58:17 UTC 
Description of problem:

rbd_snap_list_end() segfaults if rbd_snap_list() fails

Version-Release number of selected component (if applicable):

12.2.5

How reproducible:

always

Steps to Reproduce:
1. create an instance of `SnapIterator` using librbd's python binding in a very busy cluster, and rbd_snap_list() returns with ETIMEOUT
2. and `SnapIterator.__dealloc__()` gets called.


Actual results:

SIGSEGV is received. and the program crashes.

Expected results:

an exception is thrown. and the program does not crash.

Additional info:
Comment 11 Kefu Chai 2019-02-20 15:12:36 UTC 
Manohar, see the first comment in this bz

SnapIterator's constructor calls `rbd_snap_list()`, and its destructor calls rbd_snap_list_end(). i think what you need is to 

1. # unplug the network cable or whatever way to cut down the connection between your testbed to cluster
2. snap_it = SnapIterator(image)
3  del snap_it
Comment 18 errata-xmlrpc 2019-03-07 15:51:12 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://access.redhat.com/errata/RHBA-2019:0475