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CVE Record

CVE-2026-23201: ceph: fix oops due to invalid pointer for kfree() in parse_longname()

In the Linux kernel, the following vulnerability has been resolved: ceph: fix oops due to invalid pointer for kfree() in parse_longname() This fixes a kernel oops when reading ceph snapshot directories (.snap), for example by simply running `ls /mnt/my_ceph/.snap`. The variable str is guarded by __free(kfree), but advanced by one for skipping the initial '_' in snapshot names. Thus, kfree() is called with an invalid pointer. This patch removes the need for advancing the pointer so kfree() is called with correct memory pointer. Steps to reproduce: 1. Create snapshots on a cephfs volume (I've 63 snaps in my testcase) 2. Add cephfs mount to fstab $ echo "samba-fileserver@.files=/volumes/datapool/stuff/3461082b-ecc9-4e82-8549-3fd2590d3fb6 /mnt/test/stuff ceph acl,noatime,_netdev 0 0" >> /etc/fstab 3. Reboot the system $ systemctl reboot 4. Check if it's really mounted $ mount | grep stuff 5. List snapshots (expected 63 snapshots on my system) $ ls /mnt/test/stuff/.snap Now ls hangs forever and the kernel log shows the oops.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2026-23201 is a Linux kernel CephFS client bug that can make a system hang or oops when Ceph snapshot directories are read. The business risk is availability disruption for systems using CephFS snapshots, not a sourced remote takeover scenario.

Executive priority

Treat as a targeted availability risk for CephFS-dependent infrastructure. Patch during the next controlled maintenance window, sooner for file servers or production workloads where a client hang would affect users or business services.

Technical view

The issue is in CephFS parse_longname(): a string pointer guarded for kfree is advanced, causing kfree() to receive an invalid pointer. The reported trigger is reading a CephFS .snap directory. Upstream stable commits correct pointer handling.

Likely exposure

Exposure appears limited to Linux systems using CephFS mounts with snapshot directories. Systems not using CephFS snapshots are unlikely to be affected based on the provided sources. Version impact details in the bundle are incomplete and should be confirmed against kernel vendor advisories.

Exploitation context

The source describes a reproducible local filesystem interaction causing a kernel oops and hang. There is no KEV listing and no provided source claims active exploitation in the wild, privilege escalation, data theft, or remote code execution.

Researcher notes

The public bundle provides the root cause and upstream fix references but no CVSS, CWE, or detailed affected-version ranges. Avoid broad claims beyond Linux CephFS client exposure until distribution advisories clarify affected and fixed package versions.

Mitigation direction

  • Check your Linux distribution or kernel vendor advisory for fixed kernel packages.
  • Prioritize patching CephFS clients that mount volumes with snapshots.
  • Use the referenced upstream stable commits to identify backported fixes.
  • Limit unnecessary user or service access to CephFS snapshot directories where feasible.

Validation and detection

  • Inventory Linux hosts with CephFS mounts and snapshot usage.
  • Map running kernel versions to vendor fixed versions or upstream stable commits.
  • Review kernel logs for CephFS-related oops or hangs around .snap access.
  • Confirm affected hosts receive the patched CephFS client code after updates.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
0ADP providers
4Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxbb80f7618832d26f7e395f52f82b1dac76223e5f, 101841c38346f4ca41dc1802c867da990ffb32eb, 101841c38346f4ca41dc1802c867da990ffb32eb, 3145b2b11492d61c512bbc59660bb823bc757f48, 493479af8af3ab907f49e99323777d498a4fbd2b, 6.12.42, 6.15.10, 6.16.1unaffected
LinuxLinux6.17, 0, 6.12.70, 6.18.10, 6.19affected
Weakness

CWE details

No CWE listed

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