CVE-2026-98344: Linux kernel · dmaengine: Fix device kref underflow in dma_chan_put()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 01:28 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-98344 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98344 (opens in a new tab)
- git.kernel.org/linus/44dab659064eb5c10adb0306510eebe848ed592d (opens in a new tab)
- git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3 (opens in a new tab)
- git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d (opens in a new tab)
- git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d (opens in a new tab)
- git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed (opens in a new tab)
- git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef (opens in a new tab)
- git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154 (opens in a new tab)
- git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba (opens in a new tab)
- git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23 (opens in a new tab)