CVE-2026-98344
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3
- https://git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d
- https://git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d
- https://git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed
- https://git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef
- https://git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154
- https://git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba
- https://git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.