Bug 2451232 (CVE-2026-23354)

Summary: CVE-2026-23354 kernel: x86/fred: Correct speculative safety in fred_extint()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel. This vulnerability affects the handling of speculative execution, a technique used by modern processors to improve performance. A protection mechanism intended to prevent information leakage can be bypassed when its result is temporarily stored in memory, making it vulnerable to memory prediction attacks. This could allow a local attacker to potentially gain access to sensitive information or circumvent security safeguards.
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Description OSIDB Bzimport 2026-03-25 11:06:08 UTC 
In the Linux kernel, the following vulnerability has been resolved:

x86/fred: Correct speculative safety in fred_extint()

array_index_nospec() is no use if the result gets spilled to the stack, as
it makes the believed safe-under-speculation value subject to memory
predictions.

For all practical purposes, this means array_index_nospec() must be used in
the expression that accesses the array.

As the code currently stands, it's the wrong side of irqentry_enter(), and
'index' is put into %ebp across the function call.

Remove the index variable and reposition array_index_nospec(), so it's
calculated immediately before the array access.
Comment 1 Alexander B 2026-03-25 14:27:29 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026032537-CVE-2026-23354-d9b2@gregkh/T