[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
** Changed in: glib Status: Unknown => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
This bug was fixed in the package glib2.0 - 2.64.6-1~ubuntu20.04.4 --- glib2.0 (2.64.6-1~ubuntu20.04.4) focal; urgency=medium * Initialise memory used for file builder buffers to zero, since memory artifacts found themseleves into gschema.compiled files, leading to glib being unable to parse the gschema.compiled files, causing gdm, gnome-shell and various gnome applications to fail to start. (LP: #1930359) - d/p/gvdb-builder-Initialise-some-memory-to-zero-in-the-bloom-.patch -- Matthew Ruffell Mon, 12 Jul 2021 15:56:16 +0100 ** Changed in: glib2.0 (Ubuntu Focal) Status: Fix Committed => Fix Released -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
The autopkgtests worked after a retry -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
Performing verification for Focal.
I will first reproduce the problem with glib2.0 2.64.6-1~ubuntu20.04.3
from -security with the libglib2.0-0 libglib2.0-bin libglib2.0-data
packages.
I deleted all existing schemas from /usr/share/glib-2.0/schemas and
replaced them with a set of schemas which reproduce the problem easily
from my customer.
$ cd /usr/share/glib-2.0/schemas/
$ sudo rm *
$ sudo cp ~/schemas/* .
The gsettings.compiled from the customer has been corrupted, and when I
reboot, gdm fails to start and I get a blank screen with a blinking
insertion pointer.
The sha256 of the customers corrupted gsettings.compiled is:
$ sudo openssl sha256 /usr/share/glib-2.0/schemas/gschemas.compiled
SHA256(/usr/share/glib-2.0/schemas/gschemas.compiled)=
2c98dc9a7fdbac858a8d5ca7e4dd813f16058a46dba2c54b5239cd8cdba5bb3e
When I ssh back in, and recompile the file:
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas
Error parsing key “logout” in schema
“org.gnome.settings-daemon.plugins.media-keys” as specified in override file
“/usr/share/glib-2.0/schemas/50_vmware_viewagent.gschema.override”: 0-22:can
not parse as value of type 'as'. Ignoring override for this key.
$ sudo openssl sha256 /usr/share/glib-2.0/schemas/gschemas.compiled
SHA256(/usr/share/glib-2.0/schemas/gschemas.compiled)=
78163b5fefbd6320ce0d355c9531bf657a4f4dc15f057d95ef144323cd56
The sha256 has changed. Doing a bindiff, I see:
$ sudo cmp -l /home/ubuntu/schemas/gschemas.compiled
/usr/share/glib-2.0/schemas/gschemas.compiled | gawk '{printf "%08X %02X
%02X\n", $1, strtonum(0$2), strtonum(0$3)}'
376F E3 4F
3771 A4 C2
We see two bytes different. These bytes are the uninitialised memory
this bug is about. When I reboot, gdm starts fine, but that is because
this time I got lucky and the parser for the gschema.compiled file
thinks 4F and C2 are okay. But there are combinations which aren't okay,
and will end up with a corrupted gschema.compiled file.
Re-compiling the file again:
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas
Error parsing key “logout” in schema
“org.gnome.settings-daemon.plugins.media-keys” as specified in override file
“/usr/share/glib-2.0/schemas/50_vmware_viewagent.gschema.override”: 0-22:can
not parse as value of type 'as'. Ignoring override for this key.
$ sudo openssl sha256 /usr/share/glib-2.0/schemas/gschemas.compiled
SHA256(/usr/share/glib-2.0/schemas/gschemas.compiled)=
460c70faca7afc26fa88a0e5918d312478e15f20ad84f4afaa5d17627a823e01
The sha256 changed, and if we bindiff, the bytes have changed:
$ sudo cmp -l /home/ubuntu/schemas/gschemas.compiled
/usr/share/glib-2.0/schemas/gschemas.compiled | gawk '{printf "%08X %02X
%02X\n", $1, strtonum(0$2), strtonum(0$3)}'
376F E3 A6
3771 A4 A1
If we run glib-compile-schemas through valgrind, it reports that we are
writing to uninitialised memory:
https://paste.ubuntu.com/p/sxrQtbswpw/
I then enabled -proposed and installed libglib2.0-0 libglib2.0-bin
libglib2.0-data version 2.64.6-1~ubuntu20.04.4.
Now, when I re-compile the gschemas.compiled file, the sha256 matches
every time, meaning no more non-deterministic behaviour caused by
writing unitialised memory to disk:
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas
Error parsing key “logout” in schema
“org.gnome.settings-daemon.plugins.media-keys” as specified in override file
“/usr/share/glib-2.0/schemas/50_vmware_viewagent.gschema.override”: 0-22:can
not parse as value of type 'as'. Ignoring override for this key.
$ sudo openssl sha256 /usr/share/glib-2.0/schemas/gschemas.compiled
SHA256(/usr/share/glib-2.0/schemas/gschemas.compiled)=
cd9132d18b596a304251cd1eb50b64aa6fd7511a312906f9a49e1975a319fbf1
$ sudo glib-compile-schemas /usr/share/glib-2.0/schemas
Error parsing key “logout” in schema
“org.gnome.settings-daemon.plugins.media-keys” as specified in override file
“/usr/share/glib-2.0/schemas/50_vmware_viewagent.gschema.override”: 0-22:can
not parse as value of type 'as'. Ignoring override for this key.
$ sudo openssl sha256 /usr/share/glib-2.0/schemas/gschemas.compiled
SHA256(/usr/share/glib-2.0/schemas/gschemas.compiled)=
cd9132d18b596a304251cd1eb50b64aa6fd7511a312906f9a49e1975a319fbf1
Doing a bindiff, I see the changed bytes from before are now all zeros,
which is what the patch initialises the buffer to:
$ sudo cmp -l /home/ubuntu/schemas/gschemas.compiled
/usr/share/glib-2.0/schemas/gschemas.compiled | gawk '{printf "%08X %02X
%02X\n", $1, strtonum(0$2), strtonum(0$3)}'
376F E3 00
3771 A4 00
3772 55 00
Doing a run through valgrind, we no longer get a report about writing to
uninitialised memory:
https://paste.ubuntu.com/p/z52DGZcdz3/
Rebooting, the VM comes up and GDM starts properly, so glib can parse
the gsettings.compiled file without any issues.
Wonderful. The problem is fixed by the package in -proposed, happy to
mark as verified.
** Tags removed: sts-sponsor verification-needed verification-needed-focal
** Tags added:
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
Hello Matthew, or anyone else affected, Accepted glib2.0 into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/glib2.0/2.64.6-1~ubuntu20.04.4 in a few hours, and then in the -proposed repository. Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users. If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed- focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification- failed-focal. In either case, without details of your testing we will not be able to proceed. Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping! N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days. ** Changed in: glib2.0 (Ubuntu Focal) Status: In Progress => Fix Committed ** Tags added: verification-needed verification-needed-focal -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
> Looks like both of us sponsored it for the queue. I'd appreciate rejecting either one of them. I pushed to the VCS[0] at the same time as sponsoring, so I'll reject the other one which doesn't quite match up with it. [0] https://salsa.debian.org/gnome- team/glib/-/commits/ubuntu/2.64.6-1_ubuntu20.04.4/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
Thanks Iain. Looks like both of us sponsored it for the queue. I'd appreciate rejecting either one of them. Thanks! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
Thanks, sponsored to the queue -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
** Bug watch added: gitlab.gnome.org/GNOME/gvdb/-/issues #2 https://gitlab.gnome.org/GNOME/gvdb/-/issues/2 ** Also affects: glib via https://gitlab.gnome.org/GNOME/gvdb/-/issues/2 Importance: Unknown Status: Unknown ** Tags added: fixed-in-2.65.0 fixed-upstream -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/glib/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1930359] Re: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start
Attached is a debdiff for glib2.0 on Focal which fixes this problem. ** Patch added: "Debdiff for glib2.0 for Focal" https://bugs.launchpad.net/ubuntu/+source/glib2.0/+bug/1930359/+attachment/5510466/+files/lp1930359_focal.debdiff ** Tags removed: regression-update ** Tags added: sts-sponsor -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1930359 Title: glib2.0: Uninitialised memory is written to gschema.compiled, failure to parse this file leads to gdm, gnome-shell failing to start To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/glib2.0/+bug/1930359/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
