kernel-packages team mailing list archive

[Maarten Baert <maarten-baert@xxxxxxxxxxx>]

Public bug reported:

In my attempts to find an easy way to reproduce this bug:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1265684
... I actually found a very simple way to trigger a bug that is similar but not identical. I suspect that both bugs have the same cause: something in the kernel is disabling IRQs and the ext4 code will crash when this happens.

The stack trace for this bug is different from the other one. This one
appears to be less severe, the system is still usable after the crash,
only the process that caused the crash will hang (uninterruptible
sleep).

This bug is 100% reproducible on both Ubuntu 13.10 with kernel 3.11.0
and Arch Linux with kernel 3.12.6.

STEPS TO REPRODUCE
------------------

The steps to reproduce the bug are based on this:
http://www.spinics.net/lists/linux-ext4/msg38949.html

* Set up an ecryptfs 'Private' folder in your home directory.

* In that directory, create a file called 'crashme.c' with the following
code in it:

#include <assert.h>
int main() { assert(0); }

* Compile the program:

gcc -Wall crashme.c -o crashme

* Change the core dump pattern so core dumps are saved in the current
directory:

echo "coredump-%p" | sudo tee /proc/sys/kernel/core_pattern

* Enable core dumps:

ulimit -c unlimited

* Make sure that you have a second terminal open to run dmesg, because
you may not be able to do so later.

* Run 'crashme' - this will hang and trigger the bug:

./crashme

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: linux-image-3.11.0-15-generic 3.11.0-15.23
ProcVersionSignature: Ubuntu 3.11.0-15.23-generic 3.11.10
Uname: Linux 3.11.0-15-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
AudioDevicesInUse:
 USER        PID ACCESS COMMAND
 /dev/snd/controlC0:  maarten    1666 F.... lxpanel
CRDA: Error: [Errno 2] No such file or directory: 'iw'
Date: Fri Jan  3 15:58:24 2014
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=bc17e234-da75-457f-b17c-22d9c0e27dd8
InstallationDate: Installed on 2013-12-28 (6 days ago)
InstallationMedia: Lubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
IwConfig:
 eth0      no wireless extensions.
 
 lo        no wireless extensions.
MachineType: Gigabyte Technology Co., Ltd. Z87X-D3H
MarkForUpload: True
ProcFB: 0 EFI VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-15-generic.efi.signed root=UUID=5a8ae1fc-91bf-4ce0-8dea-a519976fd56b ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.11.0-15-generic N/A
 linux-backports-modules-3.11.0-15-generic  N/A
 linux-firmware                             1.116
RfKill:
 
SourcePackage: linux
StagingDrivers: zram
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/02/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: F7
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: Z87X-D3H-CF
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF7:bd08/02/2013:svnGigabyteTechnologyCo.,Ltd.:pnZ87X-D3H:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnZ87X-D3H-CF:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: Z87X-D3H
dmi.product.version: To be filled by O.E.M.
dmi.sys.vendor: Gigabyte Technology Co., Ltd.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug saucy staging

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1265841

Title:
  Kernel crash in ext4/ecryptfs after core dump in encrypted folder

Status in “linux” package in Ubuntu:
  New

Bug description:
  In my attempts to find an easy way to reproduce this bug:
  https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1265684
  ... I actually found a very simple way to trigger a bug that is similar but not identical. I suspect that both bugs have the same cause: something in the kernel is disabling IRQs and the ext4 code will crash when this happens.

  The stack trace for this bug is different from the other one. This one
  appears to be less severe, the system is still usable after the crash,
  only the process that caused the crash will hang (uninterruptible
  sleep).

  This bug is 100% reproducible on both Ubuntu 13.10 with kernel 3.11.0
  and Arch Linux with kernel 3.12.6.

  STEPS TO REPRODUCE
  ------------------

  The steps to reproduce the bug are based on this:
  http://www.spinics.net/lists/linux-ext4/msg38949.html

  * Set up an ecryptfs 'Private' folder in your home directory.

  * In that directory, create a file called 'crashme.c' with the
  following code in it:

  #include <assert.h>
  int main() { assert(0); }

  * Compile the program:

  gcc -Wall crashme.c -o crashme

  * Change the core dump pattern so core dumps are saved in the current
  directory:

  echo "coredump-%p" | sudo tee /proc/sys/kernel/core_pattern

  * Enable core dumps:

  ulimit -c unlimited

  * Make sure that you have a second terminal open to run dmesg, because
  you may not be able to do so later.

  * Run 'crashme' - this will hang and trigger the bug:

  ./crashme

  ProblemType: Bug
  DistroRelease: Ubuntu 13.10
  Package: linux-image-3.11.0-15-generic 3.11.0-15.23
  ProcVersionSignature: Ubuntu 3.11.0-15.23-generic 3.11.10
  Uname: Linux 3.11.0-15-generic x86_64
  NonfreeKernelModules: nvidia
  ApportVersion: 2.12.5-0ubuntu2.2
  Architecture: amd64
  AudioDevicesInUse:
   USER        PID ACCESS COMMAND
   /dev/snd/controlC0:  maarten    1666 F.... lxpanel
  CRDA: Error: [Errno 2] No such file or directory: 'iw'
  Date: Fri Jan  3 15:58:24 2014
  EcryptfsInUse: Yes
  HibernationDevice: RESUME=UUID=bc17e234-da75-457f-b17c-22d9c0e27dd8
  InstallationDate: Installed on 2013-12-28 (6 days ago)
  InstallationMedia: Lubuntu 13.10 "Saucy Salamander" - Release amd64 (20131016.1)
  IwConfig:
   eth0      no wireless extensions.
   
   lo        no wireless extensions.
  MachineType: Gigabyte Technology Co., Ltd. Z87X-D3H
  MarkForUpload: True
  ProcFB: 0 EFI VGA
  ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.11.0-15-generic.efi.signed root=UUID=5a8ae1fc-91bf-4ce0-8dea-a519976fd56b ro quiet splash vt.handoff=7
  RelatedPackageVersions:
   linux-restricted-modules-3.11.0-15-generic N/A
   linux-backports-modules-3.11.0-15-generic  N/A
   linux-firmware                             1.116
  RfKill:
   
  SourcePackage: linux
  StagingDrivers: zram
  UpgradeStatus: No upgrade log present (probably fresh install)
  dmi.bios.date: 08/02/2013
  dmi.bios.vendor: American Megatrends Inc.
  dmi.bios.version: F7
  dmi.board.asset.tag: To be filled by O.E.M.
  dmi.board.name: Z87X-D3H-CF
  dmi.board.vendor: Gigabyte Technology Co., Ltd.
  dmi.board.version: x.x
  dmi.chassis.asset.tag: To Be Filled By O.E.M.
  dmi.chassis.type: 3
  dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
  dmi.chassis.version: To Be Filled By O.E.M.
  dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrF7:bd08/02/2013:svnGigabyteTechnologyCo.,Ltd.:pnZ87X-D3H:pvrTobefilledbyO.E.M.:rvnGigabyteTechnologyCo.,Ltd.:rnZ87X-D3H-CF:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvrToBeFilledByO.E.M.:
  dmi.product.name: Z87X-D3H
  dmi.product.version: To be filled by O.E.M.
  dmi.sys.vendor: Gigabyte Technology Co., Ltd.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1265841/+subscriptions