In the Linux kernel, the following vulnerability has been resolved: powerpc: Avoid nmi_enter/nmi_exit in real mode interrupt. nmi_enter()/nmi_exit() touches per cpu variables which can lead to kernel crash when invoked during real mode interrupt handling (e.g. early HMI/MCE interrupt handler) if percpu allocation comes from vmalloc area. Early HMI/MCE handlers are called through DEFINE_INTERRUPT_HANDLER_NMI() wrapper which invokes nmi_enter/nmi_exit calls. We don't see any issue when percpu allocation is from the embedded first chunk. However with CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there are chances where percpu allocation can come from the vmalloc area. With kernel command line "percpu_alloc=page" we can force percpu allocation to come from vmalloc area and can see kernel crash in machine_check_early: [ 1.215714] NIP [c000000000e49eb4] rcu_nmi_enter+0x24/0x110 [ 1.215717] LR [c0000000000461a0] machine_check_early+0xf0/0x2c0 [ 1.215719] --- interrupt: 200 [ 1.215720] [c000000fffd73180] [0000000000000000] 0x0 (unreliable) [ 1.215722] [c000000fffd731b0] [0000000000000000] 0x0 [ 1.215724] [c000000fffd73210] [c000000000008364] machine_check_early_common+0x134/0x1f8 Fix this by avoiding use of nmi_enter()/nmi_exit() in real mode if percpu first chunk is not embedded.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

No data.

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 cve-icon cve-icon
https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e cve-icon cve-icon
https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 cve-icon cve-icon
https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252 cve-icon cve-icon
https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057 cve-icon cve-icon
https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2024073026-CVE-2024-42126-fdab@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2024-42126 cve-icon
https://www.cve.org/CVERecord?id=CVE-2024-42126 cve-icon
History

Tue, 05 Nov 2024 10:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 25 Oct 2024 15:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-827
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

 cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

Thu, 12 Sep 2024 08:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 11 Sep 2024 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 19 Aug 2024 04:45:00 +0000

Type Values Removed Values Added
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2024-12-19T09:13:37.693Z

Reserved: 2024-07-29T15:50:41.179Z

Link: CVE-2024-42126

cve-icon Vulnrichment

Updated: 2024-08-02T04:54:32.570Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2024-07-30T08:15:04.743

Modified: 2024-11-21T09:33:39.437

Link: CVE-2024-42126

cve-icon Redhat

Severity : Low

Publid Date: 2024-07-30T00:00:00Z

Links: CVE-2024-42126 - Bugzilla