Simple Scan crashes in Ubuntu 16 with Brother MFC-L2710DW

[Tim Newsham]

I have a Brother MFC-L2710DW printer/scanner combo. I set it up in ubuntu 16.04 using the manufacturers installer (via wifi). I can print to it fine. When I run simple scan and select the scanner in preferences, and choose to "scan all pages from feeder", it begins the scan, and then crashes.

Ubuntu 16.04.4 LTS
simple-scan:
  Installed: 3.20.0-0ubuntu1
  Candidate: 3.20.0-0ubuntu1
  Version table:
 *** 3.20.0-0ubuntu1 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status

what happened: it crashed, simple scan disappeared mid-scan
what I expected to happen: it should have completed scanning the page without crashing

[Tim Newsham (tim.newsham)]

hread 7 "scan-thread" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fffd8f7c700 (LWP 4914)]
0x00007fffd866a26f in make_cache_block ()
   from /usr/lib/x86_64-linux-gnu/sane/libsane-brother4.so.1
(gdb) where
#0 0x00007fffd866a26f in make_cache_block ()
   from /usr/lib/x86_64-linux-gnu/sane/libsane-brother4.so.1
#1 0x00007fffd866ae04 in read_scanned_data ()
   from /usr/lib/x86_64-linux-gnu/sane/libsane-brother4.so.1
#2 0x00007fffd866355e in PageScan ()
   from /usr/lib/x86_64-linux-gnu/sane/libsane-brother4.so.1
#3 0x00007fffd8673be5 in sane_brother4_read ()
   from /usr/lib/x86_64-linux-gnu/sane/libsane-brother4.so.1
#4 0x000055555557ac04 in ?? ()
#5 0x00007ffff5ff3bb5 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6 0x00007ffff53e16ba in start_thread (arg=0x7fffd8f7c700)
    at pthread_create.c:333
#7 0x00007ffff511741d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

[Tim Newsham (tim.newsham)]

It looks like the problem here is that the Brother's official driver installer
is installing an outdated driver file. This was found previously:

   https://forums.linuxmint.com/viewtopic.php?t=262330#p1425901

instead of downloading and installing the latest brscan4-0.4.5-1.amd64.deb
it is installing the older brscan4-.04.4-3.amd64.deb. This older version
is causing the crash. When the installer script is manually patched
to install the latest version of the brscan4 package, the crash goes away.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.