CVE-2021-47218

Description

In the Linux kernel, the following vulnerability has been resolved: selinux: fix NULL-pointer dereference when hashtab allocation fails When the hash table slot array allocation fails in hashtab_init(), h->size is left initialized with a non-zero value, but the h->htable pointer is NULL. This may then cause a NULL pointer dereference, since the policydb code relies on the assumption that even after a failed hashtab_init(), hashtab_map() and hashtab_destroy() can be safely called on it. Yet, these detect an empty hashtab only by looking at the size. Fix this by making sure that hashtab_init() always leaves behind a valid empty hashtab when the allocation fails.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://www.suse.com/security/cve/CVE-2021-47218.html
• https://security-tracker.debian.org/tracker/CVE-2021-47218