Bug 2467241 (CVE-2026-43274)

Summary: CVE-2026-43274 kernel: mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's mailbox subsystem, specifically within the mchp-ipc-sbi component. This vulnerability involves an out-of-bounds access in the `mchp_ipc_get_cluster_aggr_irq()` function. The `cluster_cfg` array, which holds per-CPU configuration structures, was incorrectly indexed using `hartid`, which could exceed the array's bounds. This issue can lead to memory corruption within the kernel.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-06 13:12:36 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mailbox: mchp-ipc-sbi: fix out-of-bounds access in mchp_ipc_get_cluster_aggr_irq()

The cluster_cfg array is dynamically allocated to hold per-CPU
configuration structures, with its size based on the number of online
CPUs. Previously, this array was indexed using hartid, which may be
non-contiguous or exceed the bounds of the array, leading to
out-of-bounds access.
Switch to using cpuid as the index, as it is guaranteed to be within
the valid range provided by for_each_online_cpu().
Comment 1 Vipul Nair 2026-05-06 14:00:23 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050611-CVE-2026-43274-7e15@gregkh/T