Bug 1451849
| Summary: | qemu-img convert crashes on error | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Kevin Wolf <kwolf> |
| Component: | qemu-kvm-rhev | Assignee: | Kevin Wolf <kwolf> |
| Status: | CLOSED ERRATA | QA Contact: | Ping Li <pingl> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 7.4 | CC: | aliang, chayang, coli, juzhang, knoel, michen, virt-maint |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-rhev-2.9.0-7.el7 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-08-02 04:38:29 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: | |||
Fix included in qemu-kvm-rhev-2.9.0-7.el7 Test steps: #wget http://www.valgrind.org/downloads/valgrind-3.12.0.tar.bz2 #tar -jxvf valgrind-3.12.0.tar.bz2 #cd valgrind-3.12.0 #./autogen.sh #./configure #make && make install # cat >> /home/blkdebug.cfg << eof [inject-error] event = "write_aio" sector = "819200" once = "on" eof #qemu-img create -f qcow2 /home/source.qcow2 1G #qemu-img create -f qcow2 /home/target.qcow2 1G #qemu-io -c 'write 0 1G' source.qcow2 #valgrind qemu-img convert -npWO qcow2 source.qcow2 blkdebug:/home/blkdebug.cfg:/home/target.qcow2 Reproduced the issue with below packages: kernel-3.10.0-669.el7 qemu-kvm-rhev-2.9.0-5.el7 test result: ==4108== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0) Verified the issue with below packages: kernel-3.10.0-675.el7 qemu-kvm-rhev-2.9.0-7.el7 test result: ==28177== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) 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-2017:2392 |
When an error occurs during qemu-img convert, several use-after-free errors can happen which may cause qemu to crash. The problem has been fixed upstream with commit b91127edd ('qemu-img: wait for convert coroutines to complete') and is proposed for qemu-stable. In my own testing, I could not quickly reproduce actual crashes, but using valgrind I could see errors without the patch. For reproduction, I used a blkdebug configuration file that would inject a write error after a while: [inject-error] event = "write_aio" sector = "819200" once = "on" The test run was performed with a command line like this (note that using blkdebug as the target requires that an image of the correct size is manually created and -n is used): $ valgrind qemu-img convert -npWO qcow2 $SOURCE blkdebug:/tmp/blkdebug.conf:/tmp/test.qcow2 Expected result: No valgrind errors are reported: ==2576== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0) Actual result: Valgrind does report errors: ==2657== ERROR SUMMARY: 8 errors from 2 contexts (suppressed: 0 from 0)