Crash on converting from RGB to grayscale

[Gerben Vos]

I had created an image by pasting it from the clipboard (in RGB mode but actually basically greyscale), then did a number of thresholding, select-by-colour and similar operations, then undid those all to the very beginning and converted the (original) image from RGB to greyscale, upon which the GIMP crashed.

$ lsb_release -rd
Description: Ubuntu 22.04.5 LTS
Release: 22.04
$ apt-cache policy gimp
gimp:
  Installed: 2.10.30-1ubuntu0.1
  Candidate: 2.10.30-1ubuntu0.1
  Version table:
 *** 2.10.30-1ubuntu0.1 500
        500 http://nl.archive.ubuntu.com/ubuntu jammy-updates/universe amd64 Packages
        500 http://nl.archive.ubuntu.com/ubuntu jammy-security/universe amd64 Packages
        100 /var/lib/dpkg/status
     2.10.30-1build1 500
        500 http://nl.archive.ubuntu.com/ubuntu jammy/universe amd64 Packages
$

<!-- Copy-paste this whole debug data to report to developers -->

```
GNU Image Manipulation Program version 2.10.30
git-describe: GIMP_2_10_30
Build: unknown rev 0 for linux
# C compiler #
 Using built-in specs.
 COLLECT_GCC=gcc
 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
 OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
 OFFLOAD_TARGET_DEFAULT=1
 Target: x86_64-linux-gnu
 Configured with: ../src/configure -v --with-pkgversion='Ubuntu 11.4.0-1ubuntu1~22.04' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs --enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-11 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-XeT9lY/gcc-11-11.4.0/debian/tmp-gcn/usr --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --with-build-config=bootstrap-lto-lean --enable-link-serialization=2
 Thread model: posix
 Supported LTO compression algorithms: zlib zstd
 gcc version 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)

# Libraries #
using babl version 0.1.92 (compiled against version 0.1.92)
using GEGL version 0.4.34 (compiled against version 0.4.34)
using GLib version 2.72.4 (compiled against version 2.72.4)
using GdkPixbuf version 2.42.8 (compiled against version 2.42.8)
using GTK+ version 2.24.33 (compiled against version 2.24.33)
using Pango version 1.50.6 (compiled against version 1.50.6)
using Fontconfig version 2.13.1 (compiled against version 2.13.1)
using Cairo version 1.16.0 (compiled against version 1.16.0)

```
> fatal error: Segmentation fault

Stack trace:
```

# Stack traces obtained from PID 2271304 - Thread 2271304 #

[New LWP 2271314]
[New LWP 2271315]
[New LWP 2271316]
[New LWP 2271320]
[New LWP 2271321]
[New LWP 2271326]
[New LWP 2271354]
[New LWP 2271360]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
__GI___libc_read (nbytes=256, buf=0x7ffd890bbfd0, fd=24) at ../sysdeps/unix/sysv/linux/read.c:26
  Id Target Id Frame
* 1 Thread 0x7eff9580c300 (LWP 2271304) "gimp-2.10" __GI___libc_read (nbytes=256, buf=0x7ffd890bbfd0, fd=24) at ../sysdeps/unix/sysv/linux/read.c:26
  2 Thread 0x7eff94fb8640 (LWP 2271314) "worker" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
  3 Thread 0x7eff947b7640 (LWP 2271315) "worker" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
  4 Thread 0x7eff93fb6640 (LWP 2271316) "worker" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
  5 Thread 0x7eff7affd640 (LWP 2271320) "gmain" 0x00007eff96509c3f in __GI___poll (fds=0x560f85ab0150, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
  6 Thread 0x7eff837fe640 (LWP 2271321) "gdbus" 0x00007eff96509c3f in __GI___poll (fds=0x560f85ac1900, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
  7 Thread 0x7eff737fe640 (LWP 2271326) "async" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
  8 Thread 0x7eff71ffb640 (LWP 2271354) "threaded-ml" 0x00007eff96509c3f in __GI___poll (fds=0x7eff4c015df0, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
  9 Thread 0x7eff72ffd640 (LWP 2271360) "swap writer" syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38

Thread 9 (Thread 0x7eff72ffd640 (LWP 2271360) "swap writer"):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007eff967a7ba3 in g_cond_wait () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007eff96d31c99 in () at /lib/x86_64-linux-gnu/libgegl-0.4.so.0
#3 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902702192, 682639507990310465, 139635611129408, 11, 139636203083728, 140726902702544, -826449033703133631, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#5 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 8 (Thread 0x7eff71ffb640 (LWP 2271354) "threaded-ml"):
#0 0x00007eff96509c3f in __GI___poll (fds=0x7eff4c015df0, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
        sc_ret = -516
        sc_cancel_oldtype = 0
#1 0x00007eff70eb121d in () at /lib/x86_64-linux-gnu/libpulse.so.0
#2 0x00007eff70e9a5a1 in pa_mainloop_poll () at /lib/x86_64-linux-gnu/libpulse.so.0
#3 0x00007eff70ea50bb in pa_mainloop_iterate () at /lib/x86_64-linux-gnu/libpulse.so.0
#4 0x00007eff70ea5170 in pa_mainloop_run () at /lib/x86_64-linux-gnu/libpulse.so.0
#5 0x00007eff70eb537d in () at /lib/x86_64-linux-gnu/libpulse.so.0
#6 0x00007eff709c7cb3 in () at /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-15.99.so
#7 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902711392, 682639507990310465, 139635594344000, 88, 139636203083728, 140726902711744, -826451233800131007, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#8 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 7 (Thread 0x7eff737fe640 (LWP 2271326) "async"):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007eff967a7ba3 in g_cond_wait () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x0000560f52155936 in ()
#3 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902712080, 682639507990310465, 139635619522112, 0, 139636203083728, 140726902712432, -826445734631379391, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#5 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 6 (Thread 0x7eff837fe640 (LWP 2271321) "gdbus"):
#0 0x00007eff96509c3f in __GI___poll (fds=0x560f85ac1900, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
        sc_ret = -516
        sc_cancel_oldtype = 0
#1 0x00007eff967ae256 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007eff967582b3 in g_main_loop_run () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007eff969ed7ea in () at /lib/x86_64-linux-gnu/libgio-2.0.so.0
#4 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902712064, 682639507990310465, 139635887957568, 11, 139636203083728, 140726902712416, -826903131468534207, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#6 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 5 (Thread 0x7eff7affd640 (LWP 2271320) "gmain"):
#0 0x00007eff96509c3f in __GI___poll (fds=0x560f85ab0150, nfds=2, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
        sc_ret = -516
        sc_cancel_oldtype = 0
#1 0x00007eff967ae256 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007eff967563e3 in g_main_context_iteration () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007eff96756431 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902711776, 682639507990310465, 139635745347136, 11, 139636203083728, 140726902712128, -826466625889178047, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#6 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 4 (Thread 0x7eff93fb6640 (LWP 2271316) "worker"):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007eff967a7ba3 in g_cond_wait () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007eff96cf73c3 in () at /lib/x86_64-linux-gnu/libgegl-0.4.so.0
#3 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902711936, 682639507990310465, 139636164486720, 0, 139636203083728, 140726902712288, -826939454006956479, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#5 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 3 (Thread 0x7eff947b7640 (LWP 2271315) "worker"):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007eff967a7ba3 in g_cond_wait () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007eff96cf73c3 in () at /lib/x86_64-linux-gnu/libgegl-0.4.so.0
#3 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902711936, 682639507990310465, 139636172879424, 0, 139636203083728, 140726902712288, -826953747121246655, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#5 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 2 (Thread 0x7eff94fb8640 (LWP 2271314) "worker"):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007eff967a7ba3 in g_cond_wait () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007eff96cf73c3 in () at /lib/x86_64-linux-gnu/libgegl-0.4.so.0
#3 0x00007eff96787ab1 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007eff96485ac3 in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:442
        ret = <optimized out>
        pd = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140726902711936, 682639507990310465, 139636181272128, 0, 139636203083728, 140726902712288, -826954846096003519, -826949753107714495}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
#5 0x00007eff965178c0 in clone3 () at ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81

Thread 1 (Thread 0x7eff9580c300 (LWP 2271304) "gimp-2.10"):
#0 __GI___libc_read (nbytes=256, buf=0x7ffd890bbfd0, fd=24) at ../sysdeps/unix/sysv/linux/read.c:26
        sc_ret = -512
        sc_cancel_oldtype = 0
        sc_ret = <optimized out>
#1 __GI___libc_read (fd=24, buf=0x7ffd890bbfd0, nbytes=256) at ../sysdeps/unix/sysv/linux/read.c:24
#2 0x00007eff97183c2c in gimp_stack_trace_print () at /lib/x86_64-linux-gnu/libgimpbase-2.0.so.0
#3 0x0000560f51e4772e in ()
#4 0x0000560f51e477ee in ()
#5 0x0000560f51e4784d in ()
#6 0x00007eff96433520 in <signal handler called> () at /lib/x86_64-linux-gnu/libc.so.6
#7 0x00007eff9751fee2 in gtk_widget_queue_draw () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#8 0x00007eff96851d2f in g_closure_invoke () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#9 0x00007eff9686dc36 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#10 0x00007eff9686f614 in g_signal_emit_valist () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007eff9686f863 in g_signal_emit () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007eff9685c424 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#13 0x00007eff968523ca in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007eff9686028b in g_object_thaw_notify () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#15 0x0000560f521c7e51 in gimp_image_convert_type ()
#16 0x0000560f51e676d7 in image_convert_base_type_cmd_callback ()
#17 0x00007eff96851d2f in g_closure_invoke () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#18 0x00007eff9686dc36 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#19 0x00007eff9686f614 in g_signal_emit_valist () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#20 0x00007eff9686f863 in g_signal_emit () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#21 0x0000560f51f9f6de in gimp_action_emit_change_state ()
#22 0x00007eff96851d2f in g_closure_invoke () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#23 0x00007eff9686d895 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#24 0x00007eff9686f614 in g_signal_emit_valist () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#25 0x00007eff9686f863 in g_signal_emit () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#26 0x00007eff974342cf in () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#27 0x00007eff96851d2f in g_closure_invoke () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#28 0x00007eff9686d895 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#29 0x00007eff9686f614 in g_signal_emit_valist () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#30 0x00007eff9686f863 in g_signal_emit () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#31 0x00007eff9732da6f in () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#32 0x00007eff9735d018 in () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#33 0x00007eff96851d2f in g_closure_invoke () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#34 0x00007eff9686d895 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#35 0x00007eff9686f614 in g_signal_emit_valist () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#36 0x00007eff9686f863 in g_signal_emit () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#37 0x00007eff9751e41c in gtk_widget_activate () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#38 0x00007eff97408345 in gtk_menu_shell_activate_item () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#39 0x00007eff97409ed3 in () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#40 0x00007eff973f64e7 in () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#41 0x00007eff96851d2f in g_closure_invoke () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#42 0x00007eff9686d624 in () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#43 0x00007eff9686f026 in g_signal_emit_valist () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#44 0x00007eff9686f863 in g_signal_emit () at /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#45 0x00007eff97522024 in () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#46 0x00007eff973f40a4 in gtk_propagate_event () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#47 0x00007eff973f56eb in gtk_main_do_event () at /lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
#48 0x00007eff9725917b in () at /lib/x86_64-linux-gnu/libgdk-x11-2.0.so.0
#49 0x00007eff96758d3b in g_main_context_dispatch () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#50 0x00007eff967ae2b8 in () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#51 0x00007eff967582b3 in g_main_loop_run () at /lib/x86_64-linux-gnu/libglib-2.0.so.0
#52 0x0000560f51e4ca7c in app_run ()
#53 0x0000560f51e42742 in main ()
[Inferior 1 (process 2271304) detached]

```