Created attachment 1170681 [details]
libvirtd log showing the backtrace and memory map

Description of problem:

Having GlusterFS to provide OpenStack Cinder volume storage using libgfapi causes buffer overflow when trying to create a filesystem to attached volume. This results qemu-kvm process for the instance to be terminated.

Version-Release number of selected component (if applicable):
* GlusterFS 3.8.0 on all the involved servers
* CentOS 7.1
* libvirt-daemon-1.2.8-16.el7_1.5.x86_64
* qemu-kvm-1.5.3-86.el7_1.8.x86_64

How reproducible:
Tested in three different environments and all fail similarly.

Steps to Reproduce:
1. deploy an instance
2. attach volume (of type glusterfs)
3. attempt mkfs.ext4 /dev/vdb1

Actual results:
[2016-06-22 09:15:09.350992] E [glfs-fops.c:806:glfs_io_async_cbk] (-->/usr/lib64/glusterfs/3.8.0/xlator/debug/io-stats.so(+0x11e12) [0x7eff84cb8e12] -->/lib64/libgfapi.so.0(+0xbe7d) [0x7f0000ce2e7d] -->/lib64/libgfapi.so.0(+0xbd96) [0x7f0000ce2d96] ) 0-gfapi: invalid argument: iovec [Invalid argument]
*** buffer overflow detected ***: /usr/libexec/qemu-kvm terminated

Expected results:
* filesystem to be created without crashing the instance

Additional info:
There was no such issue with 3.7.11 but we upgraded due to memory leak issues with libgfapi.