CVE-2021-47218

Name	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.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bullseye	5.10.223-1	fixed
	bullseye (security)	5.10.237-1	fixed
	bookworm	6.1.148-1	fixed
	bookworm (security)	6.1.147-1	fixed
	trixie	6.12.43-1	fixed
	trixie (security)	6.12.41-1	fixed
	forky, sid	6.16.7-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
linux	source	buster	(not affected)
linux	source	bullseye	5.10.84-1
linux	source	(unstable)	5.15.5-1

[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/dc27f3c5d10c58069672215787a96b4fae01818b (5.16-rc3)