CVE-2024-47809
kernel: dlm: fix possible lkb_resource null dereference
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · January 11, 2025
Updated · November 21, 2025
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.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference