linux-kernel - [PATCH 0/2] Quiet noisy LSM denial when accessing net sysctl

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri,  6 May 2016 18:04:12 -0500
From:	Tyler Hicks <tyhicks@...onical.com>
To:	linux-security-module@...r.kernel.org, netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc:	Serge Hallyn <serge.hallyn@...onical.com>,
	"David S . Miller" <davem@...emloft.net>
Subject: [PATCH 0/2] Quiet noisy LSM denial when accessing net sysctl

This pair of patches does away with what I believe is a useless denial
audit message when a privileged process initially accesses a net sysctl.

The bug was first discovered when running Go applications under AppArmor
confinement. It can be triggered like so:

  $ echo "profile test { file, }" | sudo apparmor_parser -rq

Once the profile is loaded, invoke Go as root under confinement:

  $ sudo aa-exec -p test -- go version
  go version go1.6.1 linux/amd64

Here's the denial:

  audit: type=1400 audit(1462575436.832:29): apparmor="DENIED" operation="capable" profile="test" pid=1157 comm="go" capability=12  capname="net_admin"

The reproducer in minimal form is:

  $ sudo aa-exec -p test -- cat /proc/sys/net/core/somaxconn
  128

The denial:

  audit: type=1400 audit(1462575670.000:29): apparmor="DENIED" operation="capable" profile="test" pid=1161 comm="cat" capability=12  capname="net_admin"

Thanks!

Tyler