Bug 2492706 (CVE-2026-53159)

Summary: CVE-2026-53159 kernel: misc: fastrpc: fix DMA address corruption due to find_vma misuse
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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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's fastrpc module. The `fastrpc_get_args()` function incorrectly calculates a Direct Memory Access (DMA) address offset for user-provided pointers. This can lead to an underflow, corrupting the DMA address sent to the Digital Signal Processor (DSP). This corruption could result in system instability or other undefined behavior.
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Description OSIDB Bzimport 2026-06-25 10:01:30 UTC 
In the Linux kernel, the following vulnerability has been resolved:

misc: fastrpc: fix DMA address corruption due to find_vma misuse

fastrpc_get_args() uses find_vma() to look up the VMA for a user-provided
pointer and compute a DMA address offset. When the address falls in a gap
before the returned VMA, (ptr & PAGE_MASK) - vma->vm_start underflows,
corrupting the DMA address sent to the DSP.

Replace find_vma() with vma_lookup(), which returns NULL when the address
is not contained within any VMA.
Comment 1 Keith Grant 2026-06-25 21:20:14 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062549-CVE-2026-53159-d6fc@gregkh/T