mutt crashed with SIGSEGV in tcache_get()

[Dan Watkins]

This happened when I wasn't interacting with mutt.

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: mutt 1.9.4-3
ProcVersionSignature: Ubuntu 4.15.0-12.13-generic 4.15.7
Uname: Linux 4.15.0-12-generic x86_64
ApportVersion: 2.20.9-0ubuntu1
Architecture: amd64
CrashCounter: 1
CurrentDesktop: ubuntu:GNOME
Date: Tue Mar 27 18:09:21 2018
ExecutablePath: /usr/bin/mutt
InstallationDate: Installed on 2017-10-23 (155 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20171018)
ProcCmdline: mutt
SegvAnalysis:
 Segfault happened at: 0x7f1bb82af207 <__GI___libc_malloc+407>: mov (%rdx),%rdi
 PC (0x7f1bb82af207) ok
 source "(%rdx)" (0x45eb0cb3bd10) not located in a known VMA region (needed readable region)!
 destination "%rdi" ok
SegvReason: reading unknown VMA
Signal: 11
SourcePackage: mutt
StacktraceTop:
 tcache_get (tc_idx=8) at malloc.c:2943
 __GI___libc_malloc (bytes=145) at malloc.c:3050
 ?? ()
 ?? ()
 ?? ()
Title: mutt crashed with SIGSEGV in tcache_get()
UpgradeStatus: Upgraded to bionic on 2018-01-23 (63 days ago)
UserGroups: adm cdrom dip docker kvm lpadmin lxd plugdev sambashare sbuild sudo

[Apport retracing service (apport)]

StacktraceTop:
 tcache_get (tc_idx=8) at malloc.c:2943
 __GI___libc_malloc (bytes=145) at malloc.c:3050
 safe_malloc (siz=<optimized out>) at ../../lib.c:151
 mutt_convert_string (ps=ps@entry=0x7ffd73bbccd0, from=from@entry=0x55eb4bdb9177 "utf-8", to=0x55eb4c717f20 "utf-8", flags=flags@entry=0) at ../../charset.c:503
 imap_utf_decode (idata=idata@entry=0x55eb4c72a410, s=s@entry=0x7ffd73bbcd00) at ../../../imap/utf7.c:283