# CVE-2026-23201

## Summary

- **CVE ID:** CVE-2026-23201
- **Severity:** MEDIUM
- **CVSS Score:** 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** N/A
- **Published:** Feb 14, 2026
- **Last Modified:** Sep 14, 2026

## Description

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.

## Affected Products

- Linux — Linux (bb80f7618832d26f7e395f52f82b1dac76223e5f)
- Linux — Linux (101841c38346f4ca41dc1802c867da990ffb32eb)
- Linux — Linux (3145b2b11492d61c512bbc59660bb823bc757f48)
- Linux — Linux (493479af8af3ab907f49e99323777d498a4fbd2b)
- Linux — Linux (6.17)
- Linux — Linux (0)
- Linux — Linux (6.12.70)
- Linux — Linux (6.18.10)
- Linux — Linux (6.19)
- Linux — Linux (6.12.42)
- Linux — Linux (6.15.10)
- Linux — Linux (6.16.1)
- Linux — Linux (4b9aee707c4580511983a0998547f3b28514e6a6)

## References

- [CNA](https://git.kernel.org/stable/c/8c9af7339de419819cfc641d551675d38ff99abf)
- [CNA](https://git.kernel.org/stable/c/e258ed369c9e04caa7d2fd49785d753ae4034cb6)
- [CNA](https://git.kernel.org/stable/c/bc8dedae022ce3058659c3addef3ec4b41d15e00)
- [CNA](https://git.kernel.org/stable/c/c9a129c82ddf82a50b4f8960d2609714ca2dbd26)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.12%
- **EPSS Percentile:** 1.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._