Bug 2467086 (CVE-2026-43281)

Summary: CVE-2026-43281 kernel: mailbox: Prevent out-of-bounds access in fw_mbox_index_xlate()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. Specifically, within the mailbox subsystem, an out-of-bounds access vulnerability exists in the `fw_mbox_index_xlate()` function. This issue arises when the device tree is configured with `#mbox-cells = <0>` and the associated mailbox controller does not provide `fw_xlate` and `of_xlate` function pointers, leading to a lack of necessary bounds checks. Exploitation of this flaw could result in system instability, potentially leading to a denial of service (DoS) or information disclosure.
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Description OSIDB Bzimport 2026-05-06 13:03:30 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mailbox: Prevent out-of-bounds access in fw_mbox_index_xlate()

Although it is guided that `#mbox-cells` must be at least 1, there are
many instances of `#mbox-cells = <0>;` in the device tree. If that is
the case and the corresponding mailbox controller does not provide
`fw_xlate` and of_xlate` function pointers, `fw_mbox_index_xlate()` will
be used by default and out-of-bounds accesses could occur due to lack of
bounds check in that function.
Comment 1 Keith Grant 2026-05-07 00:35:23 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050614-CVE-2026-43281-6031@gregkh/T