CVE-2024-42318

Summary

In the Linux kernel, the following vulnerability has been resolved:

landlock: Don't lose track of restrictions on cred_transfer

When a process' cred struct is replaced, this almost always invokes the cred_prepare LSM hook; but in one special case (when KEYCTL_SESSION_TO_PARENT updates the parent's credentials), the cred_transfer LSM hook is used instead. Landlock only implements the cred_prepare hook, not cred_transfer, so KEYCTL_SESSION_TO_PARENT causes all information on Landlock restrictions to be lost.

This basically means that a process with the ability to use the fork() and keyctl() syscalls can get rid of all Landlock restrictions on itself.

Fix it by adding a cred_transfer hook that does the same thing as the existing cred_prepare hook. (Implemented by having hook_cred_prepare() call hook_cred_transfer() so that the two functions are less likely to accidentally diverge in the future.)

Affected Software

VendorProductVersion RangeStatus
LinuxLinux385975dca53eb41031d0cbd1de318eb1bc5d6bb9 < 916c648323fa53b89eedb34a0988ddaf01406117affected
LinuxLinux385975dca53eb41031d0cbd1de318eb1bc5d6bb9 < 0d74fd54db0bd0c0c224bef0da8fc95ea9c9f36caffected
LinuxLinux385975dca53eb41031d0cbd1de318eb1bc5d6bb9 < 16896914bace82d7811c62f3b6d5320132384f49affected
LinuxLinux385975dca53eb41031d0cbd1de318eb1bc5d6bb9 < b14cc2cf313bd29056fadbc8ecd7f957cf5791ffaffected
LinuxLinux385975dca53eb41031d0cbd1de318eb1bc5d6bb9 < 39705a6c29f8a2b93cf5b99528a55366c50014d1affected
LinuxLinux5.13affected
LinuxLinux0 < 5.13unaffected
LinuxLinux5.15.165 <= 5.15.*unaffected
LinuxLinux6.1.103 <= 6.1.*unaffected
LinuxLinux6.6.44 <= 6.6.*unaffected
LinuxLinux6.10.3 <= 6.10.*unaffected
LinuxLinux6.11 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

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

References