uvcdynctrl unconditionall starts a debug log that can fill the /var partition

[Gordon Lack]

Bug 1:

/lib/udev/uvcdynctrl sets:

debug=1

which means that it creates /var/log/uvcdynctrl-udev.log and logs its startup and environment there and each invocation.

There is no related logrotate.d file to rotate this log, and there is no option to switch it off.

Bug 2:
related to the above is the fact that this script runs uvcdynctrl at the end, with the log still open.
For my webcam *this* will occasionally (once every few days) get into a loop reporting:

[libwebcam] Warning: The driver behind device video0 has a slightly buggy impl$
  of the V4L2_CTRL_FLAG_NEXT_CTRL flag. It does not return the next higher
  control ID if a control query fails. A workaround has been enabled.

This eventually (quickly?) fills the /var partition. The one I've just obtained was >8GB in size and contained > 116 million lines.

Note that even having a logrotate.d script to rotate logs wouldn't help with this.

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: uvcdynctrl 0.2.4-1.1ubuntu2 [modified: lib/udev/uvcdynctrl]
ProcVersionSignature: Ubuntu 5.8.0-26.27-generic 5.8.14
Uname: Linux 5.8.0-26-generic x86_64
ApportVersion: 2.20.11-0ubuntu50
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Sun Nov 1 11:52:52 2020
InstallationDate: Installed on 2020-08-13 (79 days ago)
InstallationMedia: Kubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
SourcePackage: libwebcam
UpgradeStatus: Upgraded to groovy on 2020-10-25 (6 days ago)

[Gordon Lack (gordon-lack)]

Here's a copy of the start of the log file produced.

Imagine the last line being repeated foreever (or at least until your /var partition was full).

[Launchpad Janitor (janitor)]

This bug was fixed in the package libwebcam - 0.2.5-2

---------------
libwebcam (0.2.5-2) unstable; urgency=medium

  * debian/control: Bump Standards-Version to 4.6.1.
  * debian/control: Restrict architecture to linux-any.
  * debian/patches: Add patch to fix package reproducibility.
    (Closes: #787999)
  * debian/changelog: Remove trailing spaces.

 -- Boyuan Yang <email address hidden> Sun, 21 Aug 2022 19:44:40 -0400

[Gordon Lack (gordon-lack)]

Doesn't fix the uvcdynctrl debug setting though.