CVE-2026-23201

Technical 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 "[email protected]=/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/st

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References