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Unrated severityNVD Advisory· Published Aug 17, 2024· Updated Nov 3, 2025

landlock: Don't lose track of restrictions on cred_transfer

CVE-2024-42318

Description

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

98

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

8

News mentions

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