CVE-2026-64590: Linux kernel · dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 6.8.0-147.147 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:49 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- Patch
- Available – fixed in 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1 +28
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Aug 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
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
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.
AI-suggested
A patch is available and has been applied in Linux kernel versions 6.8.0-147.147, 6.8.0-1067.70, 7.0.0-1012.12~24.04.1, 6.8.0-1071.79, 7.0.0-1014.14~24.04.1, and others as listed. Users should update to these fixed kernel versions to resolve the issue. No additional mitigation steps are required as the fix addresses the root cause.
Description
A Linux kernel vulnerability in the dma-buf/udmabuf subsystem caused a spurious cacheline EEXIST warning when CONFIG_DMA_API_DEBUG_SG was enabled. This warning occurred due to redundant CPU cache synchronization during dma-buf import operations, particularly affecting DRM drivers like amdgpu. The issue was fixed by skipping redundant CPU sync calls and passing the DMA_ATTR_SKIP_CPU_SYNC flag to suppress the warning and avoid unnecessary cache maintenance.
References
- ubuntu.com/security/CVE-2026-64590 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64590 (opens in a new tab)
- git.kernel.org/linus/504e2b4ab97a51d56d966cd36d0997ad30b65b2d (opens in a new tab)
- git.kernel.org/stable/c/0449a6583c0ee76778d314e4e82f166fc97fa9d8 (opens in a new tab)
- git.kernel.org/stable/c/0db56e7eae932f8e2f3eb44ad1a63633d8f504f8 (opens in a new tab)
- git.kernel.org/stable/c/34696563461c9a23177feb6d8aff43f4c0510278 (opens in a new tab)
- git.kernel.org/stable/c/504e2b4ab97a51d56d966cd36d0997ad30b65b2d (opens in a new tab)
- git.kernel.org/stable/c/d6552f5cff795d60e629f37513ecf23d88fd2f82 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)