CVE - CVE-2024-42126

CVE-ID
CVE-2024-42126	Learn more at National Vulnerability Database (NVD) • CVSS Severity Rating • Fix Information • Vulnerable Software Versions • SCAP Mappings • CPE Information
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.
References
Note: References are provided for the convenience of the reader to help distinguish between vulnerabilities. The list is not intended to be complete.
MISC:https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 URL:https://git.kernel.org/stable/c/0db880fc865ffb522141ced4bfa66c12ab1fbb70 MISC:https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e URL:https://git.kernel.org/stable/c/0f37946c62c48a907625348cbc720a7a0c547d1e MISC:https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 URL:https://git.kernel.org/stable/c/2c78c9411e685dbc9eac8c2845111b03501975b8 MISC:https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252 URL:https://git.kernel.org/stable/c/8d3f83dfb23674540c827a8d65fba20aa300b252
Assigning CNA
kernel.org
Date Record Created
20240729	Disclaimer: The record creation date may reflect when the CVE ID was allocated or reserved, and does not necessarily indicate when this vulnerability was discovered, shared with the affected vendor, publicly disclosed, or updated in CVE.
Phase (Legacy)
Assigned (20240729)
Votes (Legacy)

Comments (Legacy)

Proposed (Legacy)
N/A
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