Changing from default user to guest session and back crashes gdm

[Ara Pulido]

Binary package hint: gdm

In Lucid Alpha 1 testing.

Steps to reproduce:

 * Log in with the default user
 * Without closing the session, go to the Guest Session
 * Without closing the Guest Session, go to Switch User (the default user would appear as logged in) and select the default user
 * Without closing the session, again, go to Guest Session
 * Without closing the Guest Session, again, go to Switch User (the default user would appear as logged in) and select the default user. GDM crashes.

Apport (although I enabled it) didn't catch the crash. I will attach dmesg and syslog.

[ 92.591398] gdm-simple-slav[1775]: segfault at 28 ip 008e46ef sp bfcb78e0 error 4 in libX11.so.6.3.0[8a3000+119000]
[ 92.591522] Process 1775(gdm-simple-slav) has RLIMIT_CORE set to 0
[ 92.591524] Aborting core
[ 92.625652] gdm-session-wor[1847]: segfault at 0 ip 004156c7 sp bfb650d0 error 4 in libpam.so.0.82.1[410000+b000]
[ 92.625670] Process 1847(gdm-session-wor) has RLIMIT_CORE set to 0
[ 92.625671] Aborting core
[ 108.420521] Process 729(Xorg) has RLIMIT_CORE set to 0
[ 108.420524] Aborting core

Backtrace:
0: /usr/bin/X (xorg_backtrace+0x3b) [0x80e847b]
1: /usr/bin/X (0x8048000+0x617b5) [0x80a97b5]
2: (vdso) (__kernel_rt_sigreturn+0x0) [0x34f410]
3: /usr/lib/libpixman-1.so.0 (0x513000+0x3fc35) [0x552c35]
4: /usr/lib/libpixman-1.so.0 (0x513000+0x14569) [0x527569]
5: /usr/lib/libpixman-1.so.0 (0x513000+0x3a248) [0x54d248]
6: /usr/lib/libpixman-1.so.0 (0x513000+0x4201a) [0x55501a]
7: /usr/lib/libpixman-1.so.0 (0x513000+0x4323a) [0x55623a]
8: /usr/lib/libpixman-1.so.0 (0x513000+0x39ef3) [0x54cef3]
9: /usr/lib/libpixman-1.so.0 (0x513000+0x150e3) [0x5280e3]
10: /usr/lib/libpixman-1.so.0 (0x513000+0x3bf6e) [0x54ef6e]
11: /usr/lib/libpixman-1.so.0 (0x513000+0x150e3) [0x5280e3]
12: /usr/lib/libpixman-1.so.0 (0x513000+0x47383) [0x55a383]
13: /usr/lib/libpixman-1.so.0 (0x513000+0x150e3) [0x5280e3]
14: /usr/lib/libpixman-1.so.0 (0x513000+0x4daa9) [0x560aa9]
15: /usr/lib/libpixman-1.so.0 (0x513000+0x150e3) [0x5280e3]
16: /usr/lib/libpixman-1.so.0 (pixman_image_composite+0x16f) [0x54ddef]
17: /usr/lib/xorg/modules/libfb.so (fbComposite+0x16f) [0x3cce3f]
18: /usr/bin/X (0x8048000+0xd75db) [0x811f5db]
19: /usr/bin/X (CompositePicture+0x298) [0x8112d98]
20: /usr/bin/X (0x8048000+0x16be95) [0x81b3e95]
21: /usr/bin/X (0x8048000+0x16c00d) [0x81b400d]
22: /usr/bin/X (0x8048000+0xa3fb5) [0x80ebfb5]
23: /usr/bin/X (ConfigureWindow+0x9db) [0x809c55b]
24: /usr/bin/X (0x8048000+0x29742) [0x8071742]
25: /usr/bin/X (0x8048000+0x2a237) [0x8072237]
26: /usr/bin/X (0x8048000+0x1ec0a) [0x8066c0a]
27: /lib/tls/i686/cmov/libc.so.6 (__libc_start_main+0xe6) [0x1d9b56]
28: /usr/bin/X (0x8048000+0x1e7f1) [0x80667f1]
Segmentation fault at address 0x7f0

ProblemType: Bug
Architecture: i386
Date: Thu Dec 10 16:06:59 2009
DistroRelease: Ubuntu 10.04
EcryptfsInUse: Yes
InstallationMedia: Error: [Errno 13] Permission denied: '/var/log/installer/media-info'
Package: gdm 2.29.1-0ubuntu3
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.32-7.10-generic
SourcePackage: gdm
Tags: lucid
Uname: Linux 2.6.32-7-generic i686

[Ara Pulido (ara)]

Architecture: i386
DistroRelease: Ubuntu 10.04
EcryptfsInUse: Yes
InstallationMedia: Error: [Errno 13] Permission denied: '/var/log/installer/media-info'
Lsusb: Error: command ['lsusb'] failed with exit code 1:
MachineType: innotek GmbH VirtualBox
Package: xorg 1:7.5~3ubuntu2
PackageArchitecture: i386
PciDisplay:
 00:02.0 VGA compatible controller [0300]: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter [80ee:beef]
  Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
  Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
  Latency: 0
  Region 0: Memory at e0000000 (32-bit, prefetchable) [size=16M]
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-7-generic root=UUID=349eae8f-bfef-40ea-8b8b-008b31568402 ro quiet splash
ProcEnviron:
 SHELL=/bin/bash
 LANG=en_US.UTF-8
ProcVersionSignature: Ubuntu 2.6.32-7.10-generic
RelatedPackageVersions:
 xserver-xorg 1:7.5~3ubuntu2
 libgl1-mesa-glx 7.6.1~rc2-1ubuntu1
 libdrm2 2.4.14-1ubuntu1
 xserver-xorg-video-intel 2:2.9.1-1ubuntu1
 xserver-xorg-video-ati 1:6.12.99+git20090929.7968e1fb-0ubuntu2
Tags: lucid
Uname: Linux 2.6.32-7-generic i686
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare
XorgConf: Error: [Errno 2] No such file or directory: '/etc/X11/xorg.conf'
dmi.bios.date: 12/01/2006
dmi.bios.vendor: innotek GmbH
dmi.bios.version: VirtualBox
dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:
dmi.product.name: VirtualBox
dmi.product.version: 1.2
dmi.sys.vendor: innotek GmbH
fglrx: Not loaded
glxinfo: Error: [Errno 2] No such file or directory
system:
 distro: Ubuntu
 architecture: i686kernel: 2.6.32-7-generic

[Ara Pulido (ara)]

apport-collect data

[Ara Pulido (ara)]

apport-collect data

[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[Ara Pulido (ara)]

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[mstfa cmly (mstfacmly)]

I can confirm this on a Dell Inspiron 1546.

Pressing Ctrl+Alt+F7 showed the unlock session menu, at which point gdm started working again, but crashed another time after switching from guest to user a number of times (~3 times).

[Ara Pulido (ara)]

Bryce, can you take a look, please?

[Bryce Harrington (bryce)]

Hi Ara, it looks like this crash is occuring in libpixman although it's unclear from the X trace what routines were being called. Are you still able to reproduce this issue on current Lucid? If so please collect a full backtrace after reproducing the issue - see http://wiki.ubuntu.com/X/Backtracing for guidance. If not, then this bug can be closed. It sounds quite similar to another one I investigated a couple months ago that is now solved, but hard to say for certain.

[Bryce Harrington (bryce)]

We're closing this bug since it is has been some time with no response from the original reporter. However, if the issue still exists please feel free to reopen with the requested information. Also, if you could, please test against the latest development version of Ubuntu, since this confirms the bug is one we may be able to pass upstream for help.