Public bug reported: I have seen this failure for bionic:linux-aws-5.4 (5.4.0-1149.159~18.04.1) on aws:m5a.large instance. However, failure is due to incorrect setup and can happen on any instance if PAM (pluggable authentication modules) is misconfigured. I was not able to reproduce the issue because when I reserved m5a.large instance from aws, it was setup properly.
dmesg states "cgroup: fork rejected by pids controller in /system.slice/ssh.service" log states "tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max'" Since PAM is misconfigured, user processes cannot transition from system.slice to user.slice and thus limited by the number of processes in "/sys/fs/cgroup/pids/system.slice/ssh.service/pids.max" which is only 4915. Probably installing pam_systemd package will resolve this issue. I created this bug to hint test results. This is not a kernel regression. Some links: https://www.suse.com/support/kb/doc/?id=000019044 Full log: 09:48:46 INFO | START ubuntu_ltp_controllers.cpuacct_100_100 ubuntu_ltp_controllers.cpuacct_100_100 timestamp=1754041726 timeout=4500 localtime=Aug 01 09:48:46 09:48:46 DEBUG| Persistent state client._record_indent now set to 2 09:48:46 DEBUG| Persistent state client.unexpected_reboot now set to ('ubuntu_ltp_controllers.cpuacct_100_100', 'ubuntu_ltp_controllers.cpuacct_100_100') 09:48:46 DEBUG| Waiting for pid 8115 for 4500 seconds 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:46 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 DEBUG| [stdout] Checking for required user/group ids 09:48:46 DEBUG| [stdout] 09:48:46 DEBUG| [stdout] 'root' user id and group found. 09:48:46 DEBUG| [stdout] 'nobody' user id and group found. 09:48:46 DEBUG| [stdout] 'bin' user id and group found. 09:48:46 DEBUG| [stdout] 'daemon' user id and group found. 09:48:46 DEBUG| [stdout] Users group found. 09:48:46 DEBUG| [stdout] Sys group found. 09:48:46 DEBUG| [stdout] Required users/groups exist. 09:48:46 DEBUG| [stdout] no big block device was specified on commandline. 09:48:46 DEBUG| [stdout] Tests which require a big block device are disabled. 09:48:46 DEBUG| [stdout] You can specify it with option -z 09:48:46 DEBUG| [stdout] INFO: Test start time: Fri Aug 1 09:48:46 UTC 2025 09:48:46 DEBUG| [stdout] COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 8119 -n 8119 -f /tmp/ltp-LwNIp0yl3q/alltests -l /dev/null -C /dev/null -T /dev/null 09:48:46 DEBUG| [stdout] LOG File: /dev/null 09:48:46 DEBUG| [stdout] FAILED COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] TCONF COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] Running tests....... 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Running: cpuacct.sh 100 100 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Tested kernel: Linux ip-172-31-95-118 5.4.0-1149-aws #159~18.04.1-Ubuntu SMP Wed Jul 16 07:37:15 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Using /tmp/ltp-LwNIp0yl3q/LTP_cpuacct.vTpsrKgADv as tmpdir (ext2/ext3 filesystem) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: timeout per run is 0h 5m 0s 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: task limit fulfilled (approximate need 10000, limit 32523) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: memory requirements fulfilled (approximate need 1638400 kB, free 7431092 kB) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: cpuacct: /sys/fs/cgroup/cpu,cpuacct 09:48:47 DEBUG| [stdout] cpuacct 1 TINFO: Creating 100 subgroups each with 100 processes 09:48:51 DEBUG| [stdout] /opt/ltp/testcases/bin/cpuacct.sh: 0: /opt/ltp/testcases/bin/cpuacct.sh: Cannot fork 09:48:56 DEBUG| [stdout] INFO: ltp-pan reported some tests FAIL 09:48:56 DEBUG| [stdout] LTP Version: 20250130 09:48:56 DEBUG| [stdout] INFO: Test end time: Fri Aug 1 09:48:56 UTC 2025 09:48:56 ERROR| [stderr] ------------------------------------------- 09:48:56 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:56 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:56 ERROR| [stderr] ------------------------------------------- ** Affects: ubuntu-kernel-tests Importance: Undecided Status: New ** Description changed: I have seen this failure for bionic:linux-aws-5.4 on aws:m5a.large instance. However, failure is due to incorrect setup and can happen on any instance if PAM (pluggable authentication modules) is misconfigured. I was not able to reproduce the issue because when I reserved m5a.large instance from aws, it was setup properly. dmesg states "cgroup: fork rejected by pids controller in /system.slice/ssh.service" log states "tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max'" Since PAM is misconfigured, user processes cannot transition from system.slice to user.slice and thus limited by the number of processes in "/sys/fs/cgroup/pids/system.slice/ssh.service/pids.max" which is only 4915. - Probably installing pam_systemd package will resolve this issue. + Probably installing pam_systemd package will resolve this issue. I created this + bug to hint test results. This is not a kernel regression. Some links: https://www.suse.com/support/kb/doc/?id=000019044 - Full log: 09:48:46 INFO | START ubuntu_ltp_controllers.cpuacct_100_100 ubuntu_ltp_controllers.cpuacct_100_100 timestamp=1754041726 timeout=4500 localtime=Aug 01 09:48:46 09:48:46 DEBUG| Persistent state client._record_indent now set to 2 09:48:46 DEBUG| Persistent state client.unexpected_reboot now set to ('ubuntu_ltp_controllers.cpuacct_100_100', 'ubuntu_ltp_controllers.cpuacct_100_100') 09:48:46 DEBUG| Waiting for pid 8115 for 4500 seconds 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:46 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 DEBUG| [stdout] Checking for required user/group ids 09:48:46 DEBUG| [stdout] 09:48:46 DEBUG| [stdout] 'root' user id and group found. 09:48:46 DEBUG| [stdout] 'nobody' user id and group found. 09:48:46 DEBUG| [stdout] 'bin' user id and group found. 09:48:46 DEBUG| [stdout] 'daemon' user id and group found. 09:48:46 DEBUG| [stdout] Users group found. 09:48:46 DEBUG| [stdout] Sys group found. 09:48:46 DEBUG| [stdout] Required users/groups exist. 09:48:46 DEBUG| [stdout] no big block device was specified on commandline. 09:48:46 DEBUG| [stdout] Tests which require a big block device are disabled. 09:48:46 DEBUG| [stdout] You can specify it with option -z 09:48:46 DEBUG| [stdout] INFO: Test start time: Fri Aug 1 09:48:46 UTC 2025 09:48:46 DEBUG| [stdout] COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 8119 -n 8119 -f /tmp/ltp-LwNIp0yl3q/alltests -l /dev/null -C /dev/null -T /dev/null 09:48:46 DEBUG| [stdout] LOG File: /dev/null 09:48:46 DEBUG| [stdout] FAILED COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] TCONF COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] Running tests....... 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Running: cpuacct.sh 100 100 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Tested kernel: Linux ip-172-31-95-118 5.4.0-1149-aws #159~18.04.1-Ubuntu SMP Wed Jul 16 07:37:15 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Using /tmp/ltp-LwNIp0yl3q/LTP_cpuacct.vTpsrKgADv as tmpdir (ext2/ext3 filesystem) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: timeout per run is 0h 5m 0s 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: task limit fulfilled (approximate need 10000, limit 32523) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: memory requirements fulfilled (approximate need 1638400 kB, free 7431092 kB) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: cpuacct: /sys/fs/cgroup/cpu,cpuacct 09:48:47 DEBUG| [stdout] cpuacct 1 TINFO: Creating 100 subgroups each with 100 processes 09:48:51 DEBUG| [stdout] /opt/ltp/testcases/bin/cpuacct.sh: 0: /opt/ltp/testcases/bin/cpuacct.sh: Cannot fork 09:48:56 DEBUG| [stdout] INFO: ltp-pan reported some tests FAIL 09:48:56 DEBUG| [stdout] LTP Version: 20250130 09:48:56 DEBUG| [stdout] INFO: Test end time: Fri Aug 1 09:48:56 UTC 2025 09:48:56 ERROR| [stderr] ------------------------------------------- 09:48:56 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:56 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:56 ERROR| [stderr] ------------------------------------------- ** Description changed: - I have seen this failure for bionic:linux-aws-5.4 on aws:m5a.large - instance. However, failure is due to incorrect setup and can happen on - any instance if PAM (pluggable authentication modules) is misconfigured. - I was not able to reproduce the issue because when I reserved m5a.large - instance from aws, it was setup properly. + I have seen this failure for bionic:linux-aws-5.4 + (5.4.0-1149.159~18.04.1) on aws:m5a.large instance. However, failure is + due to incorrect setup and can happen on any instance if PAM (pluggable + authentication modules) is misconfigured. I was not able to reproduce + the issue because when I reserved m5a.large instance from aws, it was + setup properly. dmesg states "cgroup: fork rejected by pids controller in /system.slice/ssh.service" log states "tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max'" Since PAM is misconfigured, user processes cannot transition from system.slice to user.slice and thus limited by the number of processes in "/sys/fs/cgroup/pids/system.slice/ssh.service/pids.max" which is only 4915. Probably installing pam_systemd package will resolve this issue. I created this bug to hint test results. This is not a kernel regression. Some links: https://www.suse.com/support/kb/doc/?id=000019044 Full log: 09:48:46 INFO | START ubuntu_ltp_controllers.cpuacct_100_100 ubuntu_ltp_controllers.cpuacct_100_100 timestamp=1754041726 timeout=4500 localtime=Aug 01 09:48:46 09:48:46 DEBUG| Persistent state client._record_indent now set to 2 09:48:46 DEBUG| Persistent state client.unexpected_reboot now set to ('ubuntu_ltp_controllers.cpuacct_100_100', 'ubuntu_ltp_controllers.cpuacct_100_100') 09:48:46 DEBUG| Waiting for pid 8115 for 4500 seconds 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:46 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 DEBUG| [stdout] Checking for required user/group ids 09:48:46 DEBUG| [stdout] 09:48:46 DEBUG| [stdout] 'root' user id and group found. 09:48:46 DEBUG| [stdout] 'nobody' user id and group found. 09:48:46 DEBUG| [stdout] 'bin' user id and group found. 09:48:46 DEBUG| [stdout] 'daemon' user id and group found. 09:48:46 DEBUG| [stdout] Users group found. 09:48:46 DEBUG| [stdout] Sys group found. 09:48:46 DEBUG| [stdout] Required users/groups exist. 09:48:46 DEBUG| [stdout] no big block device was specified on commandline. 09:48:46 DEBUG| [stdout] Tests which require a big block device are disabled. 09:48:46 DEBUG| [stdout] You can specify it with option -z 09:48:46 DEBUG| [stdout] INFO: Test start time: Fri Aug 1 09:48:46 UTC 2025 09:48:46 DEBUG| [stdout] COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 8119 -n 8119 -f /tmp/ltp-LwNIp0yl3q/alltests -l /dev/null -C /dev/null -T /dev/null 09:48:46 DEBUG| [stdout] LOG File: /dev/null 09:48:46 DEBUG| [stdout] FAILED COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] TCONF COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] Running tests....... 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Running: cpuacct.sh 100 100 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Tested kernel: Linux ip-172-31-95-118 5.4.0-1149-aws #159~18.04.1-Ubuntu SMP Wed Jul 16 07:37:15 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Using /tmp/ltp-LwNIp0yl3q/LTP_cpuacct.vTpsrKgADv as tmpdir (ext2/ext3 filesystem) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: timeout per run is 0h 5m 0s 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: task limit fulfilled (approximate need 10000, limit 32523) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: memory requirements fulfilled (approximate need 1638400 kB, free 7431092 kB) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: cpuacct: /sys/fs/cgroup/cpu,cpuacct 09:48:47 DEBUG| [stdout] cpuacct 1 TINFO: Creating 100 subgroups each with 100 processes 09:48:51 DEBUG| [stdout] /opt/ltp/testcases/bin/cpuacct.sh: 0: /opt/ltp/testcases/bin/cpuacct.sh: Cannot fork 09:48:56 DEBUG| [stdout] INFO: ltp-pan reported some tests FAIL 09:48:56 DEBUG| [stdout] LTP Version: 20250130 09:48:56 DEBUG| [stdout] INFO: Test end time: Fri Aug 1 09:48:56 UTC 2025 09:48:56 ERROR| [stderr] ------------------------------------------- 09:48:56 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:56 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:56 ERROR| [stderr] ------------------------------------------- -- You received this bug notification because you are a member of Canonical Platform QA Team, which is subscribed to ubuntu-kernel-tests. https://bugs.launchpad.net/bugs/2119369 Title: ubuntu_ltp_controllers:cpuacct_100_100 cpuacct.sh: Cannot fork failure Status in ubuntu-kernel-tests: New Bug description: I have seen this failure for bionic:linux-aws-5.4 (5.4.0-1149.159~18.04.1) on aws:m5a.large instance. However, failure is due to incorrect setup and can happen on any instance if PAM (pluggable authentication modules) is misconfigured. I was not able to reproduce the issue because when I reserved m5a.large instance from aws, it was setup properly. dmesg states "cgroup: fork rejected by pids controller in /system.slice/ssh.service" log states "tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max'" Since PAM is misconfigured, user processes cannot transition from system.slice to user.slice and thus limited by the number of processes in "/sys/fs/cgroup/pids/system.slice/ssh.service/pids.max" which is only 4915. Probably installing pam_systemd package will resolve this issue. I created this bug to hint test results. This is not a kernel regression. Some links: https://www.suse.com/support/kb/doc/?id=000019044 Full log: 09:48:46 INFO | START ubuntu_ltp_controllers.cpuacct_100_100 ubuntu_ltp_controllers.cpuacct_100_100 timestamp=1754041726 timeout=4500 localtime=Aug 01 09:48:46 09:48:46 DEBUG| Persistent state client._record_indent now set to 2 09:48:46 DEBUG| Persistent state client.unexpected_reboot now set to ('ubuntu_ltp_controllers.cpuacct_100_100', 'ubuntu_ltp_controllers.cpuacct_100_100') 09:48:46 DEBUG| Waiting for pid 8115 for 4500 seconds 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:46 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:46 ERROR| [stderr] ------------------------------------------- 09:48:46 DEBUG| [stdout] Checking for required user/group ids 09:48:46 DEBUG| [stdout] 09:48:46 DEBUG| [stdout] 'root' user id and group found. 09:48:46 DEBUG| [stdout] 'nobody' user id and group found. 09:48:46 DEBUG| [stdout] 'bin' user id and group found. 09:48:46 DEBUG| [stdout] 'daemon' user id and group found. 09:48:46 DEBUG| [stdout] Users group found. 09:48:46 DEBUG| [stdout] Sys group found. 09:48:46 DEBUG| [stdout] Required users/groups exist. 09:48:46 DEBUG| [stdout] no big block device was specified on commandline. 09:48:46 DEBUG| [stdout] Tests which require a big block device are disabled. 09:48:46 DEBUG| [stdout] You can specify it with option -z 09:48:46 DEBUG| [stdout] INFO: Test start time: Fri Aug 1 09:48:46 UTC 2025 09:48:46 DEBUG| [stdout] COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 8119 -n 8119 -f /tmp/ltp-LwNIp0yl3q/alltests -l /dev/null -C /dev/null -T /dev/null 09:48:46 DEBUG| [stdout] LOG File: /dev/null 09:48:46 DEBUG| [stdout] FAILED COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] TCONF COMMAND File: /dev/null 09:48:46 DEBUG| [stdout] Running tests....... 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Running: cpuacct.sh 100 100 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Tested kernel: Linux ip-172-31-95-118 5.4.0-1149-aws #159~18.04.1-Ubuntu SMP Wed Jul 16 07:37:15 UTC 2025 x86_64 x86_64 x86_64 GNU/Linux 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: Using /tmp/ltp-LwNIp0yl3q/LTP_cpuacct.vTpsrKgADv as tmpdir (ext2/ext3 filesystem) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: timeout per run is 0h 5m 0s 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] tst_pid.c:84: TINFO: Cannot read session user limits from '/sys/fs/cgroup/pids/user.slice/user-1000.slice/pids.max' 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: task limit fulfilled (approximate need 10000, limit 32523) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: memory requirements fulfilled (approximate need 1638400 kB, free 7431092 kB) 09:48:46 DEBUG| [stdout] cpuacct 1 TINFO: cpuacct: /sys/fs/cgroup/cpu,cpuacct 09:48:47 DEBUG| [stdout] cpuacct 1 TINFO: Creating 100 subgroups each with 100 processes 09:48:51 DEBUG| [stdout] /opt/ltp/testcases/bin/cpuacct.sh: 0: /opt/ltp/testcases/bin/cpuacct.sh: Cannot fork 09:48:56 DEBUG| [stdout] INFO: ltp-pan reported some tests FAIL 09:48:56 DEBUG| [stdout] LTP Version: 20250130 09:48:56 DEBUG| [stdout] INFO: Test end time: Fri Aug 1 09:48:56 UTC 2025 09:48:56 ERROR| [stderr] ------------------------------------------- 09:48:56 ERROR| [stderr] INFO: runltp script is deprecated, try kirk 09:48:56 ERROR| [stderr] https://github.com/linux-test-project/kirk 09:48:56 ERROR| [stderr] ------------------------------------------- To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-kernel-tests/+bug/2119369/+subscriptions -- Mailing list: https://launchpad.net/~canonical-ubuntu-qa Post to : canonical-ubuntu-qa@lists.launchpad.net Unsubscribe : https://launchpad.net/~canonical-ubuntu-qa More help : https://help.launchpad.net/ListHelp
