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

x86/alternatives: Disable KASAN in apply_alternatives()

Fei has reported that KASAN triggers during apply_alternatives() on
a 5-level paging machine:

BUG: KASAN: out-of-bounds in rcu_is_watching()
Read of size 4 at addr ff110003ee6419a0 by task swapper/0/0
...
__asan_load4()
rcu_is_watching()
trace_hardirqs_on()
text_poke_early()
apply_alternatives()
...

On machines with 5-level paging, cpu_feature_enabled(X86_FEATURE_LA57)
gets patched. It includes KASAN code, where KASAN_SHADOW_START depends on
__VIRTUAL_MASK_SHIFT, which is defined with cpu_feature_enabled().

KASAN gets confused when apply_alternatives() patches the
KASAN_SHADOW_START users. A test patch that makes KASAN_SHADOW_START
static, by replacing __VIRTUAL_MASK_SHIFT with 56, works around the issue.

Fix it for real by disabling KASAN while the kernel is patching alternatives.

[ mingo: updated the changelog ]
Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-6831-1 Linux kernel vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 11 Dec 2024 15:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.6:rc5:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 6.0, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:H'}

cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T07:38:09.999Z

Reserved: 2024-02-20T12:30:33.314Z

Link: CVE-2023-52504

cve-icon Vulnrichment

Updated: 2024-08-02T23:03:20.409Z

cve-icon NVD

Status : Analyzed

Published: 2024-03-02T22:15:47.300

Modified: 2024-12-11T15:05:44.313

Link: CVE-2023-52504

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-03-02T00:00:00Z

Links: CVE-2023-52504 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses