The CIL compiler in SELinux 3.2 has a use-after-free in cil_reset_classpermission (called from cil_reset_classperms_set and cil_reset_classperms_list). References: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=32177 https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-536.yaml Upstream patch: https://github.com/SELinuxProject/selinux/commit/c49a8ea09501ad66e799ea41b8154b6770fec2c8
Created libsepol tracking bugs for this issue: Affects: fedora-all [bug 1979667]
selinux/libsepol is mostly local access and to perform this attack would require local access as compared to network access. An attacker would also require some form of privileges to write the policy file and compile the CIL. The availability impact is also low as this flaw would not cause a system wide or complete lack of availability. Instead the attack would only impact availability of selinux temporarily.
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:4513 https://access.redhat.com/errata/RHSA-2021:4513
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2021-36086
*** Bug 2184112 has been marked as a duplicate of this bug. ***