Bug#791888: lvm2: segfaults when activating LVs other than /

[Nicolas Noirbent]

Package: libdevmapper1.02.1
Version: 2:1.02.90-2.2
Severity: important

Dear Maintainer,

After upgrading to the latest version of libdevmapper1.02.1 from
unstable, I found myself unable to mount my /home logical volume due
to a segfault in libdevmapper.so.1.02.1:

# grep segfault /var/log/kern.log
Jul  9 11:20:46 briareos kernel: [    8.184718] lvm[1639]: segfault at 80 ip 00007f80cf3f14ef sp 00007ffe0aa24050 error 4 in libdevmapper.so.1.02.1[7f80cf3d9000+46000]
Jul  9 11:20:46 briareos kernel: [   30.719648] lvchange[1955]: segfault at 80 ip 00007f4c1ebf14ef sp 00007ffef827eca0 error 4 in libdevmapper.so.1.02.1[7f4c1ebd9000+46000]
Jul  9 11:20:46 briareos kernel: [   84.536668] lvchange[1990]: segfault at 80 ip 00007fad611b74ef sp 00007ffda2685610 error 4 in libdevmapper.so.1.02.1[7fad6119f000+46000]

I'm filing this bug against libdevmapper1.02.1 specifically since the
lvm2 package itself was not upgraded due to apt-listbugs pinning it
following https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=791869

Here's what I ran on my system when in the boot maintenance shell:

# dpkg -l lvm2 libdevmapper1.02.1
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name                                                                       Version                                    Architecture                               Description
+++-==========================================================================-==========================================-==========================================-=========================================================================================================================================================
ii  libdevmapper1.02.1:amd64                                                   2:1.02.99-1                                amd64                                      Linux Kernel Device Mapper userspace library
ii  lvm2                                                                       2.02.111-2.2                               amd64                                      Linux Logical Volume Manager
# apt-cache policy lvm2 libdevmapper1.02.1
lvm2:
  Installed: 2.02.111-2.2
  Candidate: 2.02.111-2.2
  Package pin: 2.02.111-2.2
  Version table:
     2.02.122-1 1000
        500 http://debian.proxad.net/debian/ sid/main amd64 Packages
 *** 2.02.111-2.2 1000
        500 http://debian.proxad.net/debian/ jessie/main amd64 Packages
        100 /var/lib/dpkg/status
libdevmapper1.02.1:
  Installed: 2:1.02.99-1
  Candidate: 2:1.02.99-1
  Version table:
 *** 2:1.02.99-1 0
        500 http://debian.proxad.net/debian/ sid/main amd64 Packages
        100 /var/lib/dpkg/status
     2:1.02.90-2.2 0
        500 http://debian.proxad.net/debian/ jessie/main amd64 Packages
# lvchange -a y /dev/mapper/vg_raid5-home
zsh: segmentation fault  lvchange -a y /dev/mapper/vg_raid5-home


Downgrading the lvm2, libdevmapper1.02.1 and dmeventd to their jessie
versions fixed the issue.

In case someone encounters the same problem, for some strange reason
in the boot maintenance shell /usr/sbin was not in my $PATH so I had
to add it by hand:

# export PATH=$PATH:/usr/sbin

Before running:

# apt install libdevmapper1.02.1/jessie lvm2/jessie dmeventd/jessie

Else the installation would fail due to missing executables (namely
update-initramfs).

Regards,

-- System Information:
Debian Release: stretch/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (500, 'stable'), (101, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.0.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages libdevmapper1.02.1:amd64 depends on:
ii  dmsetup            2:1.02.90-2.2
ii  libc6              2.19-18
ii  libselinux1        2.3-2+b1
ii  libudev1           222-1
ii  multiarch-support  2.19-18

libdevmapper1.02.1:amd64 recommends no packages.

libdevmapper1.02.1:amd64 suggests no packages.

-- no debconf information