Red Hat Bugzilla – Bug 505408
SELinux error on logout - SELinux is preventing kdm (xdm_t) "execute" bootloader_exec_t.
Last modified: 2009-06-11 17:49:34 EDT
+++ This bug was initially created as a clone of Bug #503061 +++ Bug #503061 was - SELinux policy prevents krb5 logins Description of problem: Get the following error on logout. Version-Release number of selected component (if applicable): selinux-policy-3.6.12-44.fc11.noarch How reproducible: Very Steps to Reproduce: 1. Login to KDE then logout Actual results: Get selinux alert on logout Expected results: No selinux alerts on logout Additional info: Copied the following information from seaudit -g : Summary: SELinux is preventing kdm (xdm_t) "execute" bootloader_exec_t. Detailed Description: SELinux denied access requested by kdm. It is not expected that this access is r equired by kdm and this access may signal an intrusion attempt. It is also possi ble that the specific version or configuration of the application is causing it to require additional access. Allowing Access: You can generate a local policy module to allow this access - see FAQ Or you can disable SELinux protection altogether. Disabling SELinux protection is not reco mmended. Please file a bug report against this package. Additional Information: Source Context: system_u:system_r:xdm_t:s0-s0:c0.c1023 Target Context: system_u:object_r:bootloader_exec_t:s0 Target Objects: grub [ file ] Source: kdmSource Path: /usr/bin/kdm Port: <Unknown> Host: hostname.deleted Source RPM Packages: kdm-4.2.3-5.fc11 Target RPM Packages: Policy RPM: selinux-policy-3.6.12-44.fc11 Selinux Enabled: True Policy Type: targeted MLS Enabled: True Enforcing Mode: Enforcing Plugin Name: catchall Host Name: hostname.deleted Platform: Linux hostname.deleted 2.6.29.4-167.fc11.x86_64 #1 SMP Wed May 27 17: 27:08 EDT 2009 x86_64 x86_64 Alert Count: 6 First Seen: Wed 03 Jun 2009 09:12:39 AM MDT Last Seen: Thu 11 Jun 2009 10:25:48 AM MDT Local ID: 53dfc5c0-9319-4b81-a5b1-9f832b6f0f54 Line Numbers: Raw Audit Messages : node=hostname.deleted type=AVC msg=audit(1244737548.319:27226): avc: denied { ex ecute } for pid=1978 comm="kdm" name="grub" dev=dm-0 ino=60363 scontext=system_u :system_r:xdm_t:s0-s0:c0.c1023 tcontext=system_u:object_r:bootloader_exec_t:s0 t class=file node=hostname.deleted type=SYSCALL msg=audit(1244737548.319:27226): arch=c000003 e syscall=21 success=no exit=-13 a0=7fffaa72d966 a1=1 a2=0 a3=10 items=0 ppid=1 pid=1978 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="kdm" exe="/usr/bin/kdm" subj=system_u:system_r: xdm_t:s0-s0:c0.c1023 key=(null)
Unlike the previous, copied Bug #503061, this one is limited to KDE.
This is not supported by SELinux if you want to add this support you can do so using audit2allow. ALlowing the login screen to modify grub without logging in is considered by the selinux security team to be a security problem, which is why it is turned off by default.