Bug 2297528 (CVE-2024-40944)

Summary:	CVE-2024-40944 kernel: x86/kexec: Fix bug with call depth tracking
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 6.6.35, kernel 6.9.6, kernel 6.10-rc3	Doc Type:	If docs needed, set a value
Doc Text:	A vulnerability was found in the Linux kernel's x86/kexec component, where the function call to cc_platform_has() could lead to a system crash when call depth tracking is active. This issue occurs because the GS segment is reset by load_segments(), setting GS_BASE to 0, while call depth tracking relies on per-CPU variables.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2024-07-12 13:37:35 UTC

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

x86/kexec: Fix bug with call depth tracking

The call to cc_platform_has() triggers a fault and system crash if call depth
tracking is active because the GS segment has been reset by load_segments() and
GS_BASE is now 0 but call depth tracking uses per-CPU variables to operate.

Call cc_platform_has() earlier in the function when GS is still valid.

  [ bp: Massage. ]