CVE Catalog

CVE-2026-98344

Low risk· EPSS 8%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

8th percentile - higher than 8% of all known CVEs

Summary

In the Linux kernel, dma_chan_put() unconditionally dropped the device reference while dma_chan_get() only took it on the slow path. This caused a kref underflow on every fast-path get/put pair.

Risk Assessment

When the kref reaches zero, dma_find_channel() returns NULL even though the provider module is still loaded, potentially causing crashes or DMA channel unavailability.

Recommendation

Update the Linux kernel to a version with the fix that drops device->ref only on the last put, matching the single slow-path get.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: dmaengine: Fix device kref underflow in dma_chan_put() dma_chan_get() takes chan->device->ref only on the slow path: /* no kref on fast path */ if (chan->client_count) { __module_get(owner); chan->client_count++; return 0; } if (!try_module_get(owner)) return -ENODEV; if (!dma_device_get(chan->device)) { // calls kref_get_unless_zero() dma_chan_put() drops the ref unconditionally, so every fast-path get/put pair drops one extra device reference. The bug fires when two conditions hold together: a non-private provider has a persistent client holding chan->client_count > 0 and another client cycles dmaengine_get()/dmaengine_put(). When the kref hits zero, the subsequent dma_find_channel() returns NULL even though the provider module is still loaded. Fix this by dropping device->ref only on the last put, matching the single slow-path get.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS