CVE-2026-89576: Linux kernel · dm-era: fix shadowed superblock leak on take-snap failure
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 28 Oct 2026, 01:01 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
Exploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 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: dm-era: fix shadowed superblock leak on take-snap failure metadata_take_snap() bumps the live superblock refcount and then dm_tm_shadow_block() allocates a new block for the metadata snapshot. If the subsequent dm_sm_inc_block() of writeset_tree_root or era_array_root fails, the function only unlocks the clone and returns. The newly allocated shadow block is never returned to the metadata space map, so each failed take-snap permanently leaks one metadata block. Free the clone with dm_sm_dec_block() on those error paths, matching the final step of metadata_drop_snap().
References
- ubuntu.com/security/CVE-2026-89576 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89576 (opens in a new tab)
- git.kernel.org/linus/39c5aa3bd8ec3912d2cd0b3fe092642b0d2b0713 (opens in a new tab)
- git.kernel.org/stable/c/36ff918637e3517f732188a3c39dbeae5b9cfb1b (opens in a new tab)
- git.kernel.org/stable/c/39c5aa3bd8ec3912d2cd0b3fe092642b0d2b0713 (opens in a new tab)
- git.kernel.org/stable/c/6876ca330e741fb8886d12070cb6a7f9cb67257e (opens in a new tab)
- git.kernel.org/stable/c/d66ceeefb87ddb097b0546bafc581380b816b048 (opens in a new tab)