Bug 1350789

+++ This bug was initially created as a clone of Bug #1349276 +++

+++ This bug was initially created as a clone of Bug #1348935 +++

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.

--- Additional comment from Joe Julian on 2016-06-22 10:36:58 EDT ---

Unless I'm reading this wrong, every place that glfs_io_async_cbk is called, the return value is never checked so when that error takes place, none of the unrefs or frees are ever done.

--- Additional comment from Vijay Bellur on 2016-06-23 03:03:19 EDT ---

REVIEW: http://review.gluster.org/14779 (gfapi : check the value "iovec" in glfs_io_async_cbk only for read) posted (#1) for review on master by jiffin tony Thottan (jthottan)

--- Additional comment from Vijay Bellur on 2016-06-23 03:19:29 EDT ---

REVIEW: http://review.gluster.org/14779 (gfapi : check the value "iovec" in glfs_io_async_cbk only for read) posted (#2) for review on master by jiffin tony Thottan (jthottan)

--- Additional comment from Vijay Bellur on 2016-06-27 07:49:21 EDT ---

REVIEW: http://review.gluster.org/14779 (gfapi : check the value "iovec" in glfs_io_async_cbk only for read) posted (#3) for review on master by jiffin tony Thottan (jthottan)

--- Additional comment from Vijay Bellur on 2016-06-27 07:52:45 EDT ---

REVIEW: http://review.gluster.org/14779 (gfapi : check the value "iovec" in glfs_io_async_cbk only for read) posted (#4) for review on master by jiffin tony Thottan (jthottan)

--- Additional comment from Vijay Bellur on 2016-06-28 07:21:59 EDT ---

COMMIT: http://review.gluster.org/14779 committed in master by Kaleb KEITHLEY (kkeithle) 
------
commit 61d72b3d91f2655b04de4ef29262f738a8cf7369
Author: Jiffin Tony Thottan <jthottan>
Date:   Thu Jun 23 12:20:03 2016 +0530

    gfapi : check the value "iovec" in glfs_io_async_cbk only for read
    
    The glfs_io_async_cbk() is called from the cbk of all the async ops
    such as write, read, fsync, ftruncate. In all other cases, expect for
    read the value for "iovec" is NULL. From the code, glfs_io_async_cbk
    checks the value in common routine which may end up in failures.
    
    Thanks Joe Julian for finding issue and suggesting the fix.
    
    Change-Id: I0be0123da68f9d8fbb5d94ede2d45566a9add6a5
    BUG: 1349276
    Signed-off-by: Jiffin Tony Thottan <jthottan>
    Reported-by: Joe Julian <me>
    Reviewed-on: http://review.gluster.org/14779
    Reviewed-by: Niels de Vos <ndevos>
    Smoke: Gluster Build System <jenkins.org>
    Tested-by: Kaleb KEITHLEY <kkeithle>
    NetBSD-regression: NetBSD Build System <jenkins.org>
    CentOS-regression: Gluster Build System <jenkins.org>
    Reviewed-by: Joe Julian <me>