VulnerabilityPublished 4 Sep 2026Updated 30 Sep 2026

CVE-2026-80809: Linux kernel · ocfs2: fix missing metadata reservation for large xattrs

Affects Linux kernelSource GCVE Database

Not known to be exploited.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-4q7v-w8cm-5gq2

What to do

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-34.34 22 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1013.13 14 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1014.14 14 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1013.13 8 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1013.13 12 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1007.8 5 affected builds	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 fix has been implemented in the Linux kernel to address this issue by adding the missing metadata reservation and replacing the kernel panic with an error return. Users should update to the fixed kernel version once available.

Description

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix missing metadata reservation for large xattrs [BUG] lsetxattr() panics the kernel when setting a large xattr value on a fragmented filesystem where the file already has an external xattr block. [CAUSE] ocfs2_calc_xattr_set_need() never reserves metadata blocks for a new xattr value's extent tree when the file already has an external xattr block. The not_found path leaves meta_add at zero, so meta_ac is NULL when ocfs2_xattr_extend_allocation() runs. A new value root has room for a single extent record. On a fragmented filesystem, the allocator cannot satisfy the xattr value in one contiguous run, so each non-contiguous run requires its own extent record. When the value root's extent list is full and meta_ac is NULL, ocfs2_add_clusters_in_btree() returns RESTART_META, and ocfs2_xattr_extend_allocation() hits BUG_ON(why == RESTART_META). [FIX] The case where no xattr block exists yet already calls ocfs2_extend_meta_needed(&def_xv.xv.xr_list) to reserve value tree metadata. Add the same reservation to the case where an xattr block already exists, making the two cases consistent. Replace the BUG_ON with a -ENOSPC return so that if RESTART_META is returned despite the reservation, the error propagates to userspace instead of panicking the kernel.

Impact

The vulnerability could cause a denial of service by panicking the kernel when large extended attributes are set on certain fragmented filesystems using ocfs2. This results in system instability or crashes. There is no indication of privilege escalation or data corruption beyond the kernel panic.

Summary

The Linux kernel ocfs2 filesystem had a bug in the lsetxattr() function where setting a large xattr value on a fragmented filesystem with an existing external xattr block caused a kernel panic. This was due to ocfs2_calc_xattr_set_need() failing to reserve metadata blocks for the new xattr value's extent tree when an external xattr block already existed. As a result, the allocator could not handle fragmented extents properly, leading to a BUG_ON panic in ocfs2_xattr_extend_allocation(). The patch added metadata reservation in this case and replaced the BUG_ON panic with a -ENOSPC error return to userspace, preventing kernel crashes.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Sep 2026, 11:53 UTC

Technical details

References

Community reviews

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