Various files and directories created with odd permissions on precise

[Jamie Strandboge]

When performing install audits of yesterday's 12.04 isos, I found the following odd directory on servers:

$ ls -ld /media/
drwsrwsrwt 3 root root 4096 Apr 13 06:06 /media/

In 11.10 we had:
drwxr-xr-x root root

The desktop install does not seem to be affected:
$ ls -ld /media/
drwxr-xr-x 2 root root 4096 Apr 12 02:42 /media/

Other directories:
drwsrwsrwt 2 root root 40 Apr 13 06:59 /run/initramfs/ (desktop and server)
drwsrwsrwt 2 root root 4096 Apr 13 07:21 /var/lib/apt/lists/partial (server only)

Some odd files:
crw------T 1 root root 10, 235 Apr 13 07:18 /dev/autofs
crw------T 1 root root 10, 234 Apr 13 07:18 /dev/btrfs-control
crw------T 1 root root 10, 184 Apr 13 07:18 /dev/cpu/microcode
crw-rw-rwT 1 root fuse 10, 229 Apr 13 07:18 /dev/fuse
crw-rw-rwT 1 root root 10, 200 Apr 13 07:18 /dev/net/tun
crw-rw---T 1 root audio 116, 1 Apr 13 07:18 /dev/snd/seq
crw-rw---T 1 root audio 116, 33 Apr 13 07:18 /dev/snd/timer

Server files were observed after first boot of a amd64 server install (non-MAAS) with encrypted home and all (non-manual) tasks installed in a kvm VM. All other options were defaults.

Desktop files were observed after first boot of a amd64 livecd install with encrypted home and 3rd party addons selected in a kvm VM. All other options were defaults.

[Colin Watson (cjwatson)]

/run/initramfs would be a problem (non-rlimitable DoS due to memory use), but I can't reproduce that on desktop.

[Colin Watson (cjwatson)]

With the exception of the device node permissions (which aren't an installer problem, if they're a problem; please file these against udev if you believe them to be problems), I can't reproduce any of these. Please provide logs.

[Steve Langasek (vorlon)]

Reproduced the /run/initramfs setting here on desktop on a fresh install, as well as the wrong perms in /dev.

I even see this on my running desktop, which is an upgrade.

And /run and /dev are both tmpfses populated at boot time, so this isn't an installer issue.

[Jamie Strandboge (jdstrand)]

Here is the installer for the livecd.

[Jamie Strandboge (jdstrand)]

Here is the installer log for the server.

[Jamie Strandboge (jdstrand)]

Added a udev task, but I checked udev for several of this and don't see why the stick bit would be set. Is a umask being improperly set somewhere that is fiddling with the first octal?

[Steve Langasek (vorlon)]

Rather than opening new tasks for every package this *might* be, let's stick it on udev for now (since it's reproducible on upgrades and therefore not an installer issue) and I'll see what I can find out.

I'm currently suspecting an issue in the interactions between plymouth, cryptsetup, initramfs-tools, and udev.

[Steve Langasek (vorlon)]

with 'break=top', I've reproduced the wrong perms on /run/initramfs within the initramfs itself - so before any initramfs hook scripts have run. The umask of the shell is correct (0022); the permissions on the directory created with mkdir are wrong. This may be a busybox bug.

[Steve Langasek (vorlon)]

$ /usr/lib/initramfs-tools/bin/busybox mkdir test
$ ls -ld test
drwsrwsrwt 2 vorlon vorlon 40 Apr 13 11:19 test
$

[Steve Langasek (vorlon)]

mkdir("test", 0777) = 0
chmod("test", 037777777777) = 0

[Launchpad Janitor (janitor)]

This bug was fixed in the package busybox - 1:1.18.5-1ubuntu4

---------------
busybox (1:1.18.5-1ubuntu4) precise; urgency=low

  * debian/patches/fix-64-bit-permissions.patch: mkdir: fix permissions
    on 64-bit platforms. Taken from upstream. LP: #980772.
 -- Steve Langasek <email address hidden> Fri, 13 Apr 2012 12:32:35 -0700

[Jamie Strandboge (jdstrand)]

For the sticky bits on device files, Colin found in the udev source that as of udev 174, the sticky bit is used on files to indicate that the kernel module for the corresponding device file should not be unloaded. This corresponds to:
https://bugzilla.redhat.com/show_bug.cgi?id=724920#c9