Bug 667912 (CVE-2011-0006)
| Summary: | CVE-2011-0006 kernel: ima: fix add LSM rule bug | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | Eugene Teo (Security Response) <eteo> |
| Component: | vulnerability | Assignee: | Red Hat Product Security <security-response-team> |
| Status: | CLOSED ERRATA | QA Contact: | |
| Severity: | low | Docs Contact: | |
| Priority: | low | ||
| Version: | unspecified | CC: | arozansk, eparis, kernel-mgr, kmcmartin, lwang, tcallawa, vkrizan, wnefal+redhatbugzilla |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2015-07-29 13:37:14 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
| Bug Depends On: | 667914, 667915 | ||
| Bug Blocks: | |||
Statement: The Linux kernel as shipped with Red Hat Enterprise Linux 4, 5, and Red Hat Enterprise MRG are not affected by this issue. A future kernel update in Red Hat Enterprise Linux 6 may address this flaw. This issue has been addressed in following products: Red Hat Enterprise Linux 6 Via RHSA-2011:0498 https://rhn.redhat.com/errata/RHSA-2011-0498.html |
If security_filter_rule_init() doesn't return a rule, then not everything is as fine as the return code implies. This bug only occurs when the LSM (eg. SELinux) is disabled at runtime. Adding an empty LSM rule causes ima_match_rules() to always succeed, ignoring any remaining rules. default IMA TCB policy: # PROC_SUPER_MAGIC dont_measure fsmagic=0x9fa0 # SYSFS_MAGIC dont_measure fsmagic=0x62656572 # DEBUGFS_MAGIC dont_measure fsmagic=0x64626720 # TMPFS_MAGIC dont_measure fsmagic=0x01021994 # SECURITYFS_MAGIC dont_measure fsmagic=0x73636673 < LSM specific rule > dont_measure obj_type=var_log_t measure func=BPRM_CHECK measure func=FILE_MMAP mask=MAY_EXEC measure func=FILE_CHECK mask=MAY_READ uid=0 Thus without the patch, with the boot parameters 'tcb selinux=0', adding the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB measurement policy, would result in nothing being measured. The patch prevents the default TCB policy from being replaced. Upstream commit: http://git.kernel.org/linus/867c20265459d30a01b021a9c1e81fb4c5832aa9 Introduced in 2.6.30-rc1 4af4662f