CVE-2026-72315: Linux kernel · smb: client: fix busy dentry warning on unmount after DIO
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 7.0.0-1014.14~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1014.14~24.04.1, 7.0.0-1017.17~24.04.1, 7.0.0-1016.16~24.04.1 +11
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 15 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.
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 that fixes this issue by implementing a per-superblock outstanding request counter and waiting for all cleanup work to complete before unmounting. Users should apply the official Linux kernel updates that include this fix. The vendor advisory confirms the availability of the fix. No additional mitigation steps are required beyond applying the patch.
Description
A vulnerability in the Linux kernel's SMB client implementation caused a busy dentry warning on unmount due to delayed release of dentry reference counts in the CIFS DIO path. This issue was fixed by introducing a per-superblock outstanding request counter and waiting for all cleanup work to complete before unmounting, preventing use-after-release conditions. The vulnerability affects specific Linux kernel versions and has a CVSS score of 7.8, indicating a high impact on confidentiality, integrity, and availability.
References
- nvd.nist.gov/vuln/detail/CVE-2026-72315 (opens in a new tab)
- git.kernel.org/stable/c/75f5c412fa867efa0bf9b646bffe0d912109e84a (opens in a new tab)
- git.kernel.org/stable/c/f0eac9c3c3711f24efc2aaf12b8ec3e54a38c214 (opens in a new tab)
- ubuntu.com/security/CVE-2026-72315 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-72315 (opens in a new tab)
- git.kernel.org/linus/75f5c412fa867efa0bf9b646bffe0d912109e84a (opens in a new tab)
- git.kernel.org/stable/c/9fc87899276af941ecf3045798887db7deb85605 (opens in a new tab)
- git.kernel.org/stable/c/f7748b551010c021d92f0125e37f32ac0c376d8a (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)