CVE-2021-47218

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux03414a49ad5f3c56988c36d2070e402ffa17feaf < b17dd53cac769dd13031b0ca34f90cc65e523fabaffected
LinuxLinux03414a49ad5f3c56988c36d2070e402ffa17feaf < 83c8ab8503adf56bf68dafc7a382f4946c87da79affected
LinuxLinux03414a49ad5f3c56988c36d2070e402ffa17feaf < dc27f3c5d10c58069672215787a96b4fae01818baffected
LinuxLinux5.8affected
LinuxLinux0 < 5.8unaffected
LinuxLinux5.10.82 <= 5.10.*unaffected
LinuxLinux5.15.5 <= 5.15.*unaffected
LinuxLinux5.16 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

CVE Program Container

Additional References

References