Bug 1430225

Summary: kernel: fix crash in uio_release
Product: Red Hat Enterprise Linux 7 Reporter: Mike Christie <mchristi>
Component: kernelAssignee: Mike Christie <mchristi>
kernel sub component: Kernel Target (LIO) QA Contact: Martin Hoyer <mhoyer>
Status: CLOSED ERRATA Docs Contact:
Severity: unspecified    
Priority: high CC: amukherj, cleech, coughlan, hnallurv, mchristi, prasanna.kalever, rcyriac, salmy, tgill
Version: 7.4   
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: kernel-3.10.0-690.el7 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2017-08-02 05:50:07 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: 1408292, 1449245, 1468963    

Description Mike Christie 2017-03-08 04:57:08 UTC 
Description of problem:

We hit this crash when adding/deleting devices:

https://lkml.org/lkml/2015/3/11/514

The problem is that target_core_user calls tcmu_free_device -> tcmu_netlink_event (TCMU_CMD_REMOVED_DEVICE) -> uio_unregister_device. It does not wait for the TCMU_CMD_REMOVED_DEVICE userspace handler to close the uio device, so if the uio_unregister_device is faster than userspace we will hit the uio_release crash because the uio_device will be freed.


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Additional info:
Comment 14 Rafael Aquini 2017-06-29 03:05:28 UTC 
Patch(es) committed on kernel repository and an interim kernel build is undergoing testing
Comment 16 Rafael Aquini 2017-06-29 12:34:16 UTC 
Patch(es) available on kernel-3.10.0-690.el7
Comment 18 Martin Hoyer 2017-07-04 08:18:58 UTC 
Regression tests on RHEL-7.4-20170630.1 w/ kernel-3.10.0-691.el7 have not found any new issue. Moving to VERIFIED as per comment#11
Comment 20 errata-xmlrpc 2017-08-02 05:50:07 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/RHSA-2017:1842