CVE-2024-47809 Information

Description

In the Linux kernel the following vulnerability has been resolved:

dlm: fix possible lkb_resource null dereference

This patch fixes a possible null pointer dereference when this function is called from request_lock() as lkb->lkb_resource is not assigned yet only after validate_lock_args() by calling attach_lkb(). Another issue is that a resource name could be a non printable bytearray and we cannot assume to be ASCII coded.

The log functionality is probably never being hit when DLM is used in normal way and no debug logging is enabled. The null pointer dereference can only occur on a new created lkb that does not have the resource assigned yet it probably never hits the null pointer dereference but we should be sure that other changes might not change this behaviour and we actually can hit the mentioned null pointer dereference.

In this patch we just drop the printout of the resource name the lkb id is enough to make a possible connection to a resource name if this exists.

Reference

https://git.kernel.org/stable/c/2db11504ef82a60c1a2063ba7431a5cd013ecfcb https://git.kernel.org/stable/c/6fbdc3980b70e9c1c86eccea7d5ee68108008fa7 https://git.kernel.org/stable/c/b98333c67daf887c724cd692e88e2db9418c0861