CVE-2024-42318: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Linux Linux Kernel: from 5.13, before 5.15.165 (fixed in 5.15.165); from 5.16, before 6.1.103 (fixed in 6.1.103); from 6.2, before 6.6.44 (fixed in 6.6.44); from 6.7, before 6.10.3 (fixed in 6.10.3)

Published 2024-08-17. Last modified 2026-08-04.