Bug#990998: libx11-6: new version causes segfault for fdesign

[Matt Zagrabelny <mzagrabe@d.umn.edu>]

Package: libx11
Version: 2:1.7.1-1
Severity: normal

Dear Maintainer,

When I launch fdesign (from libforms-bin) and click on the menu (File, Form,
Group, Options, etc.) the program segfaults.

libforms-bin hasn't seen any version changes in a long time. The debugger and
some empirical evidence suggests it was the libx11 change from version 2:1.7.0-2
to version 2:1.7.1-1.

Here is the debugging backtrace:

$ gdb fdesign
[...]
(No debugging symbols found in fdesign)
(gdb) run
Starting program: /usr/bin/fdesign

Program received signal SIGSEGV, Segmentation fault.
__strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:65
65      ../sysdeps/x86_64/multiarch/strlen-avx2.S: No such file or directory.
(gdb) back
#0  __strlen_avx2 () at ../sysdeps/x86_64/multiarch/strlen-avx2.S:65
#1  0x00007ffff7de1505 in XStoreName () from /lib/x86_64-linux-gnu/libX11.so.6
#2  0x00007ffff7f5553f in fl_showpup () from /lib/libforms.so.2
#3  0x00007ffff7f558a4 in fl_dopup () from /lib/libforms.so.2
#4  0x00007ffff7f2efef in ?? () from /lib/libforms.so.2
#5  0x00007ffff7f2f604 in ?? () from /lib/libforms.so.2
#6  0x00007ffff7f3200b in ?? () from /lib/libforms.so.2
#7  0x00007ffff7f33068 in fli_handle_object () from /lib/libforms.so.2
#8  0x00007ffff7f27751 in fli_handle_form () from /lib/libforms.so.2
#9  0x00007ffff7f2892f in fli_treat_interaction_events () from
/lib/libforms.so.2
#10 0x00007ffff7f28f77 in fl_do_forms () from /lib/libforms.so.2
#11 0x0000555555572332 in ?? ()
#12 0x00007ffff7c03d0a in __libc_start_main (main=0x55555557139b,
argc=1, argv=0x7fffffffe0a8, init=<optimized out>,
    fini=<optimized out>, rtld_fini=<optimized out>,
stack_end=0x7fffffffe098) at ../csu/libc-start.c:308
#13 0x000055555556748a in ?? ()

When I downgrade libx11-6 to version 2:1.7.0-2, fdesign no longer segfaults
and works properly.

Thank you for supporting free software. It is appreciated!


-- System Information:
Debian Release: 11.0
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'unstable'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 5.10.0-8-amd64 (SMP w/12 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled