CVE-2024-42126
powerpc: Avoid nmi_enter/nmi_exit in real mode interrupt.
Description
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.
INFO
Published Date :
July 30, 2024, 8:15 a.m.
Last Modified :
Oct. 6, 2025, 5:15 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the affected kernel packages.
- Reboot the system after updating.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2024-42126.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-42126 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-42126
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2024-42126 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-42126 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Oct. 06, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.9.9 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.39 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.98 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.165 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.10 up to (excluding) 5.10.224 Added Reference Type CVE: https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 Types: Patch Added Reference Type CVE: https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848 Types: Patch -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 Added Reference https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e Added Reference https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 Added Reference https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252 -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 19, 2024
Action Type Old Value New Value Added Reference kernel.org https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057 [No types assigned] -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 30, 2024
Action Type Old Value New Value Added Description 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. Added Reference kernel.org https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 [No types assigned]