CVE-2024-42126

MEDIUM EPSS 13.5%
Published Jul 30, 20241y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Jul 30, 2024 1y ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
13.5% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 5

VendorProductVersionRange
linuxlinux_kernel*≥5.10  –  <5.10.224
linuxlinux_kernel*≥5.11  –  <5.15.165
linuxlinux_kernel*≥5.16  –  <6.1.98
linuxlinux_kernel*≥6.2  –  <6.6.39
linuxlinux_kernel*≥6.7  –  <6.9.9

References 7

  • git.kernel.org https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/e2afb26615adf6c3ceaaa7732aa839bcd587a057
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fb6675db04c4b79883373edc578d5df7bbc84848
    Patch