** Description changed: + SRU justification: + + [Impact] + + * The NX server (and derivatives e.g. FreeNX, X2Go) and Xvnc server + (and derivatives e.g. tightvncserver, xrdp) do not support the IDLETIME + counter. Violating the assumption that this is available leads to gnome- + session (in trusty) or unity-settings-daemon (in utopic) crashing when + trying to set up an idle monitor. + + * This bug renders GNOME Flashback unusable on the mentioned X servers. + Per the justification in bug 1251281, these collectively affect quite a + few users, particularly on the LTS which tends to be chosen when setting + up a terminal server. + + * The proposed patch adds missing precondition checks to + gnome_idle_monitor_get_idletime, avoiding the crash. Other public entry + points to the idle monitor library already have similar checks. + + [Test Case] + + * Install gnome-session-flashback, tightvncserver, and vncviewer. + + * If bug 1251281 is not fixed in -updates yet: install gnome-session- + bin from -proposed (needed for --disable-acceleration-check). + + * Create ~/.vnc/xstartup with the following content (3 lines): + + #!/bin/sh + export STARTUP="gnome-session --session=gnome-flashback --disable-acceleration-check" + exec /etc/X11/Xsession + + * Make it executable: chmod +x ~/.vnc/xstartup + + * Log out from the desktop, log in on a tty, and run: vncserver :1 + + * Log in to the desktop as a guest, and run: vncviewer :1 + + Expected results: a GNOME Flashback VNC session is started. + + Actual results: + - trusty: gnome-session crashes on startup. + - utopic: gnome-session starts, but unity-settings-daemon crashes, so gnome-session gives up shortly after (because it's a required component). + + [Regression Potential] + + * The patch was accepted in unity-settings-daemon for vivid and there + were no regression reports so far. + + * There should be no changes observed under a conventional local (Xorg) + session. + + [Other Info] + + * Packages for testing are available in ppa:rtandy/flashback. So far at least one user reported success using those packages in comment 68 on bug 1251281. + + Original description: + The X server used by FreeNX and X2Go does not support the IDLETIME counter. This eventually leads to a NULL pointer dereference by gnome- session due to a missing parameter check in gnome_idle_monitor_get_idletime. This renders GNOME Flashback unusable via FreeNX/X2Go in Trusty. Utopic and newer are not affected and the patch is not applicable as the GnomeIdleMonitor implementation was rewritten. Saucy is also affected but is EOL, however I would like to fix this in Trusty as the patch is tiny and IMO obviously correct. This and bug #1251281 are the only bugs preventing GNOME Flashback being used via FreeNX/X2Go in Trusty; and the latter has an easy workaround (divert the acceleration-check helper and replace it with /bin/true) and may be fixed properly soon. I would be happy to prepare a debdiff and fill out the SRU template if a sponsor agrees that the patch is SRUable. ProblemType: Crash DistroRelease: Ubuntu 14.04 Package: gnome-session-bin 3.9.90-0ubuntu12 [modified: usr/lib/gnome-session/gnome-session-check-accelerated usr/lib/gnome-session/gnome-session-check-accelerated-helper] ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4 Uname: Linux 3.13.0-32-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.6 Architecture: amd64 CasperVersion: 1.340 Date: Thu Jan 29 19:28:42 2015 ExecutablePath: /usr/bin/gnome-session ExecutableTimestamp: 1394758239 LiveMediaBuild: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2) ProcCmdline: /usr/bin/gnome-session --session=gnome-flashback ProcCwd: /home/ubuntu ProcEnviron: - PATH=(custom, no user) - XDG_RUNTIME_DIR=<set> - LANG=en_US.UTF-8 - SHELL=/bin/bash - LD_LIBRARY_PATH=<set> + PATH=(custom, no user) + XDG_RUNTIME_DIR=<set> + LANG=en_US.UTF-8 + SHELL=/bin/bash + LD_LIBRARY_PATH=<set> SegvAnalysis: - Segfault happened at: 0x7fb690b29196 <gnome_idle_monitor_get_idletime+6>: mov 0x18(%rdi),%rax - PC (0x7fb690b29196) ok - source "0x18(%rdi)" (0x00000018) not located in a known VMA region (needed readable region)! - destination "%rax" ok + Segfault happened at: 0x7fb690b29196 <gnome_idle_monitor_get_idletime+6>: mov 0x18(%rdi),%rax + PC (0x7fb690b29196) ok + source "0x18(%rdi)" (0x00000018) not located in a known VMA region (needed readable region)! + destination "%rax" ok SegvReason: reading NULL VMA Signal: 11 SourcePackage: gnome-session StacktraceTop: - gnome_idle_monitor_get_idletime (monitor=0x0) at gnome-idle-monitor.c:613 - reset_idle_watch (presence=0x7fb6780036f0) at gsm-presence.c:196 - gsm_presence_set_idle_enabled (presence=0x7fb6780036f0, enabled=1) at gsm-presence.c:354 - start_phase (manager=manager@entry=0x1658100) at gsm-manager.c:1568 - end_phase (manager=manager@entry=0x1658100) at gsm-manager.c:580 + gnome_idle_monitor_get_idletime (monitor=0x0) at gnome-idle-monitor.c:613 + reset_idle_watch (presence=0x7fb6780036f0) at gsm-presence.c:196 + gsm_presence_set_idle_enabled (presence=0x7fb6780036f0, enabled=1) at gsm-presence.c:354 + start_phase (manager=manager@entry=0x1658100) at gsm-manager.c:1568 + end_phase (manager=manager@entry=0x1658100) at gsm-manager.c:580 Title: gnome-session crashed with SIGSEGV in gnome_idle_monitor_get_idletime() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-desktop3 in Ubuntu. https://bugs.launchpad.net/bugs/1416081 Title: (FreeNX/X2Go) gnome-session crashed with SIGSEGV in gnome_idle_monitor_get_idletime() Status in gnome-desktop3 package in Ubuntu: New Status in unity-settings-daemon package in Ubuntu: Fix Released Bug description: SRU justification: [Impact] * The NX server (and derivatives e.g. FreeNX, X2Go) and Xvnc server (and derivatives e.g. tightvncserver, xrdp) do not support the IDLETIME counter. Violating the assumption that this is available leads to gnome-session (in trusty) or unity-settings-daemon (in utopic) crashing when trying to set up an idle monitor. * This bug renders GNOME Flashback unusable on the mentioned X servers. Per the justification in bug 1251281, these collectively affect quite a few users, particularly on the LTS which tends to be chosen when setting up a terminal server. * The proposed patch adds missing precondition checks to gnome_idle_monitor_get_idletime, avoiding the crash. Other public entry points to the idle monitor library already have similar checks. [Test Case] * Install gnome-session-flashback, tightvncserver, and vncviewer. * If bug 1251281 is not fixed in -updates yet: install gnome-session- bin from -proposed (needed for --disable-acceleration-check). * Create ~/.vnc/xstartup with the following content (3 lines): #!/bin/sh export STARTUP="gnome-session --session=gnome-flashback --disable-acceleration-check" exec /etc/X11/Xsession * Make it executable: chmod +x ~/.vnc/xstartup * Log out from the desktop, log in on a tty, and run: vncserver :1 * Log in to the desktop as a guest, and run: vncviewer :1 Expected results: a GNOME Flashback VNC session is started. Actual results: - trusty: gnome-session crashes on startup. - utopic: gnome-session starts, but unity-settings-daemon crashes, so gnome-session gives up shortly after (because it's a required component). [Regression Potential] * The patch was accepted in unity-settings-daemon for vivid and there were no regression reports so far. * There should be no changes observed under a conventional local (Xorg) session. [Other Info] * Packages for testing are available in ppa:rtandy/flashback. So far at least one user reported success using those packages in comment 68 on bug 1251281. Original description: The X server used by FreeNX and X2Go does not support the IDLETIME counter. This eventually leads to a NULL pointer dereference by gnome- session due to a missing parameter check in gnome_idle_monitor_get_idletime. This renders GNOME Flashback unusable via FreeNX/X2Go in Trusty. Utopic and newer are not affected and the patch is not applicable as the GnomeIdleMonitor implementation was rewritten. Saucy is also affected but is EOL, however I would like to fix this in Trusty as the patch is tiny and IMO obviously correct. This and bug #1251281 are the only bugs preventing GNOME Flashback being used via FreeNX/X2Go in Trusty; and the latter has an easy workaround (divert the acceleration-check helper and replace it with /bin/true) and may be fixed properly soon. I would be happy to prepare a debdiff and fill out the SRU template if a sponsor agrees that the patch is SRUable. ProblemType: Crash DistroRelease: Ubuntu 14.04 Package: gnome-session-bin 3.9.90-0ubuntu12 [modified: usr/lib/gnome-session/gnome-session-check-accelerated usr/lib/gnome-session/gnome-session-check-accelerated-helper] ProcVersionSignature: Ubuntu 3.13.0-32.57-generic 3.13.11.4 Uname: Linux 3.13.0-32-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.6 Architecture: amd64 CasperVersion: 1.340 Date: Thu Jan 29 19:28:42 2015 ExecutablePath: /usr/bin/gnome-session ExecutableTimestamp: 1394758239 LiveMediaBuild: Ubuntu 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.2) ProcCmdline: /usr/bin/gnome-session --session=gnome-flashback ProcCwd: /home/ubuntu ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash LD_LIBRARY_PATH=<set> SegvAnalysis: Segfault happened at: 0x7fb690b29196 <gnome_idle_monitor_get_idletime+6>: mov 0x18(%rdi),%rax PC (0x7fb690b29196) ok source "0x18(%rdi)" (0x00000018) not located in a known VMA region (needed readable region)! destination "%rax" ok SegvReason: reading NULL VMA Signal: 11 SourcePackage: gnome-session StacktraceTop: gnome_idle_monitor_get_idletime (monitor=0x0) at gnome-idle-monitor.c:613 reset_idle_watch (presence=0x7fb6780036f0) at gsm-presence.c:196 gsm_presence_set_idle_enabled (presence=0x7fb6780036f0, enabled=1) at gsm-presence.c:354 start_phase (manager=manager@entry=0x1658100) at gsm-manager.c:1568 end_phase (manager=manager@entry=0x1658100) at gsm-manager.c:580 Title: gnome-session crashed with SIGSEGV in gnome_idle_monitor_get_idletime() UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-desktop3/+bug/1416081/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp