** Tags added: apport-collected ** Description changed:
Install Ubuntu 12.04, then upgrade to the latest kernel-image. Create a filesystem like: mkdir orig move various picture files into "orig", then do ln orig/* . now you'll have a directory with the original files in "orig" and hardlinked copies in "." Next start up digikam, work on these hardlinked pictures: change them, add or delete comments, upload them ... Next step: run find . -size 0 You'll find all pictures you've worked on in "orig" to show up with size 0! The original data contained in these is lost. No recover. The files are actually of zero size! It is not only digicam, but others to: as soon as a file is read, and then overwritten, all not opened hardlinked files show zero size. Only the one file you've opened keeps its size and holds data. I've found this behaviour with: - digikam - rsync - kate I am assuming the kernel not korrectly handling hardlinks under certain circumstances. Only possible workaround at the moment: do not use hardlinks! Copy files! The bug may be used to zero out configuration files and, if they are empty gain access to things no access was granted, if you do ln /etc/configfile /home/user/configfile then work on /home/user/configfile. /etc/configfile will, after this operation, have size 0 and hold nothing. It is at least possible to use it for denial of service, if services depend on configfiles and do not accept empty ones. ProblemType: Bug DistroRelease: Ubuntu 12.04 Package: bash 4.2-2ubuntu2 Uname: Linux 3.4.10 x86_64 ApportVersion: 2.0.1-0ubuntu13 Architecture: amd64 Date: Mon Sep 17 12:29:14 2012 InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) ProcEnviron: LANGUAGE=de_DE:en TERM=screen-bce PATH=(custom, user) LANG=de_DE.UTF-8 SHELL=/bin/bash SourcePackage: bash UpgradeStatus: Upgraded to precise on 2012-07-16 (62 days ago) modified.conffile..etc.bash.bashrc: [modified] modified.conffile..etc.skel..bashrc: [modified] mtime.conffile..etc.bash.bashrc: 2012-07-16T19:54:47.049684 mtime.conffile..etc.skel..bashrc: 2012-07-16T19:42:08.188571 + --- + ApportVersion: 2.0.1-0ubuntu13 + Architecture: amd64 + DistroRelease: Ubuntu 12.04 + InstallationMedia: Xubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012) + Package: linux (not installed) + ProcEnviron: + LANGUAGE=de_DE:en + TERM=screen-bce + PATH=(custom, no user) + LANG=de_DE.UTF-8 + SHELL=/bin/bash + Tags: precise + Uname: Linux 3.4.11 x86_64 + UnreportableReason: The running kernel is not an Ubuntu kernel + UpgradeStatus: Upgraded to precise on 2012-07-16 (63 days ago) + UserGroups: pkcs11 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1051901 Title: Files hardlinked to others may be set to zero size To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1051901/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
