seetxt crashed with SIGSEGV in _IO_vfprintf_internal()

[Nathaniel Beaver]

Steps to reproduce:

1. Open seetxt

2. Open the manpage.

3. Click the button on the bottom-right corner to the right of the "regexp" button. Observe flickering.

4. Close the program.

5. Program throws a segmentation fault.

These steps do not always result in SIGSEGV. On my machine, it occurred the first time I ran seetxt, but I had to try it 3 or 4 times again to replicate it. I suspect this is due to a race condition.

I can provide more extensive backtraces for each thread from gdb if necessary.

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: seetxt 0.72-6
ProcVersionSignature: Ubuntu 4.15.0-39.42-generic 4.15.18
Uname: Linux 4.15.0-39-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CrashCounter: 1
CurrentDesktop: KDE
Date: Tue Dec 4 16:10:52 2018
ExecutablePath: /usr/bin/seetxt
InstallationDate: Installed on 2018-04-27 (221 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
ProcCmdline: seetxt
SegvAnalysis:
 Segfault happened at: 0x7fde76771646 <__strlen_sse2+38>: movdqu (%rax),%xmm4
 PC (0x7fde76771646) ok
 source "(%rax)" (0x00001001) not located in a known VMA region (needed readable region)!
 destination "%xmm4" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: see
StacktraceTop:
 _IO_vfprintf_internal (s=s@entry=0x7ffd7659c3a0, format=format@entry=0x55794ef73c2e "Manual Page for \"%s\"", ap=ap@entry=0x7ffd7659c4e0) at vfprintf.c:1643
 ___vsprintf_chk (s=0x7ffd7659c5e0 "Manual Page for \"...", flags=1, slen=384, format=0x55794ef73c2e "Manual Page for \"%s\"", args=args@entry=0x7ffd7659c4e0) at vsprintf_chk.c:82
 ___sprintf_chk (s=<optimized out>, flags=<optimized out>, slen=<optimized out>, format=<optimized out>) at sprintf_chk.c:31
 sprintf (__fmt=0x55794ef73c2e "Manual Page for \"%s\"", __s=0x7ffd7659c5e0 "Manual Page for \"...") at /usr/include/x86_64-linux-gnu/bits/stdio2.h:33
 loadman (setline=0) at see.c:1345
Title: seetxt crashed with SIGSEGV in _IO_vfprintf_internal()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm audio bluetooth cdrom dialout dip floppy lpadmin netdev plugdev sambashare scanner sudo systemd-journal tty vboxusers video wireshark

[Apport retracing service (apport)]

StacktraceTop:
 _IO_vfprintf_internal (s=s@entry=0x7ffd7659c3a0, format=format@entry=0x55794ef73c2e "Manual Page for \"%s\"", ap=ap@entry=0x7ffd7659c4e0) at vfprintf.c:1643
 ___vsprintf_chk (s=0x7ffd7659c5e0 "Manual Page for \"...", flags=1, slen=384, format=0x55794ef73c2e "Manual Page for \"%s\"", args=args@entry=0x7ffd7659c4e0) at vsprintf_chk.c:82
 ___sprintf_chk (s=<optimized out>, flags=<optimized out>, slen=<optimized out>, format=<optimized out>) at sprintf_chk.c:31
 sprintf (__fmt=0x55794ef73c2e "Manual Page for \"%s\"", __s=0x7ffd7659c5e0 "Manual Page for \"...") at /usr/include/x86_64-linux-gnu/bits/stdio2.h:33
 loadman (setline=0) at see.c:1345