profile-14.04-trusty-lp1717714.debdiff ** Patch added: "profile-14.04-trusty-lp1717714.debdiff" https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/1717714/+attachment/5047667/+files/profile-14.04-trusty-lp1717714.debdiff
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to apparmor in Ubuntu. https://bugs.launchpad.net/bugs/1717714 Title: @{pid} variable broken on systems with pid_max more than 6 digits Status in AppArmor: Fix Committed Status in AppArmor 2.11 series: Fix Committed Status in apparmor package in Ubuntu: Fix Released Status in apparmor source package in Trusty: Fix Committed Status in apparmor source package in Xenial: Fix Committed Status in apparmor source package in Artful: Fix Committed Status in apparmor source package in Bionic: Fix Released Status in apparmor package in Debian: Fix Released Bug description: [Impact] If PID is larger than 6 digits apparmor denies process which only affect 64-bit systems[1] where the PID_MAX_LIMIT can be generated up to 7 digits at the maximum. This fix is committed, but not released. so all supporting version are affected. [1] - man 5 proc -------------------------------------------------------------------------- /proc/sys/kernel/pid_max (since Linux 2.5.34) This file specifies the value at which PIDs wrap around (i.e., the value in this file is one greater than the maximum PID). PIDs greater than this value are not allocated; thus, the value in this file also acts as a system-wide limit on the total number of processes and threads. The default value for this file, 32768, results in the same range of PIDs as on ear‐lier kernels. On 32-bit platforms, 32768 is the maximum value for pid_max. On 64-bit systems, pid_max can be set to any value up to 2^22 (PID_MAX_LIMIT, approximately 4 million). -------------------------------------------------------------------------- [Test Case] 1. making pid over 6 digits #!/bin/bash for i in {1..1000000} do touch t done 2. snap install --dangerous core_16-2.29.4.2_amd64.snap ( snap core 16-2.30 avoids using /proc/PID/cmdline, so need to use older version 3. you can see DENIED msgs in syslog 4. change /etc/apparmor.d/tunables/kernelvars 5. service apparmor restart 6. service snapd restart 7. DENIED is gone This is one way, can't reproduce this issue again even if you change back to original kernelvars, and restart snapd OR instead of Seyeong's touch approach, things can be manually change to 7 digits range via sysctl as long as the values are below approximately 4 millions : Example: $ sysctl -w kernel.pid_max=3000000 $ sysctl -w kernel.ns_last_pid=1000000 [Regression] * This is a minor/trivial fix which changes the pid regex only, allowing 7 digits PID instead of only 6 digits PID, we don't think there is any potential regression. * If a regression arise, which we highly doubt, one can quickly revert the change manually and restart the service by modifying "/etc/apparmor.d/tunables/kernelvars" file to its original state (before this SRU). [Others] * Upstream commit: https://gitlab.com/apparmor/apparmor/commit/630cb2a981cdc731847e8fdaafc45bcd337fe747 http://bazaar.launchpad.net/~apparmor-dev/apparmor/master/revision/3722 * Debian bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=886732 * commit 630cb2a981cdc731847e8fdaafc45bcd337fe747 Author: Vincas Dargis <vin...@gmail.com> Date: Sat Sep 30 15:28:15 2017 +0300 Allow seven digit pid * Affecting releases : TXZAB -------------------------------------------------------------------------- $ git describe --contains 630cb2a9 v2.11.95~5^2 $ rmadison apparmor apparmor | 2.8.95~2430-0ubuntu5 | trusty apparmor | 2.10.95-0ubuntu2.6~14.04.1 | trusty-security apparmor | 2.10.95-0ubuntu2.6~14.04.1 | trusty-updates apparmor | 2.10.95-0ubuntu2 | xenial apparmor | 2.10.95-0ubuntu2.6 | xenial-security apparmor | 2.10.95-0ubuntu2.7 | xenial-updates apparmor | 2.11.0-2ubuntu4 | zesty apparmor | 2.11.0-2ubuntu17 | artful apparmor | 2.11.0-2ubuntu18 | bionic $ rmadison -u debian apparmor apparmor | 2.11.1-4 | unstable -------------------------------------------------------------------------- [Original Description] If your kernel.pid_max sysctl is set higher than the default, say at 7 digits, the @{pid} variable no longer matches all pids, causing some breakage in any profile using it. @{pid} is defined in /etc/apparmor.d/tunables: @{pid}={[1-9],[1-9][0-9],[1-9][0-9][0-9],[1-9][0-9][0-9][0-9],[1-9][0-9][0-9][0-9][0-9],[1-9][0-9][0-9][0-9][0-9][0-9]} It only covers up to 6 digits. This Ubuntu 17.04 system has: kernel.pid_max = 4194303 And is showing type=1400 audit(1505588857.828:792): apparmor="DENIED" operation="open" profile="libvirt-55e9e12c-e6dc-4f56-a547-8514cf7d9bf3" name="/proc/2168180/task/2769256/comm" pid=2168180 comm="qemu-system-x86" requested_mask="wr" denied_mask="wr" fsuid=111 ouid=111 Which should be matched by @{PROC}/sys/vm/overcommit_memory r, in /etc/apparmor.d/abstractions/libvirt-qemu I'm seeing similar failures on 16.04 (2.10.95-0ubuntu2.7), 17.04 (2.11.0-2ubuntu4) and 17.10 (2.11.0-2ubuntu17) I am aware this is a non-default configuration, but I think this should work. To manage notifications about this bug go to: https://bugs.launchpad.net/apparmor/+bug/1717714/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
