CVE-2026-72146: dmaengine: sh: rz-dmac: Move interrupt request after everything is set up
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: sh: rz-dmac: Move interrupt request after everything is set up
Once the interrupt is requested, the interrupt handler may run immediately. Since the IRQ handler can access channel->chbase, which is initialized only after requesting the IRQ, this may lead to invalid memory access. Likewise, the IRQ thread may access uninitialized data (the ldfree, ldqueue, and ldactive lists), which may also lead to issues.
Request the interrupts only after everything is set up. To keep the error path simpler, use dmamalloccoherent() instead of dmaalloccoherent().
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Move the interrupt request (request_irq) so it occurs only after setup of structures and pointers referenced by the IRQ handler (e.g., channel->ch_base, ld_free, ld_queue, ld_active) is complete; do not request the interrupt before initialization.
dmaengine (sh rz-dmac) interrupt request timing = Request IRQ only after all driver data structures are initialized - Configuration
Update the driver to use dmam_alloc_coherent() rather than dma_alloc_coherent() for coherent DMA allocations, per the referenced fix guidance.
dmaengine (sh rz-dmac) coherent DMA allocation API = Use dmam_alloc_coherent() instead of dma_alloc_coherent()
Event History
Frequently Asked Questions
What is the severity of CVE-2026-72146?
The severity of CVE-2026-72146 is rated at risk level 37.
How do I fix CVE-2026-72146?
To fix CVE-2026-72146, ensure that the interrupt request is moved after all necessary initializations are completed in the drivers.
What systems are affected by CVE-2026-72146?
CVE-2026-72146 affects the Linux kernel with specific configurations involving the dmaengine and rz-dmac driver.
What is the impact of CVE-2026-72146?
The impact of CVE-2026-72146 includes potential system instability or erroneous behavior due to premature access by the interrupt handler.
When was CVE-2026-72146 published?
CVE-2026-72146 was published on August 15, 2026.