The CIL compiler in SELinux 3.2 has a use-after-free in __cil_verify_classperms (called from __verify_map_perm_classperms and hashtab_map).
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
Link | Tags |
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https://github.com/google/oss-fuzz-vulns/blob/main/vulns/selinux/OSV-2021-421.yaml | third party advisory |
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=31124 | patch exploit third party advisory issue tracking |
https://github.com/SELinuxProject/selinux/commit/2d35fcc7e9e976a2346b1de20e54f8663e8a6cba | third party advisory patch |
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U7ZYR3PIJ75N6U2IONJWCKZ5L2NKJTGR/ | vendor advisory |