NULL pointer dereference in Linux
CVE-2026-23201
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.
EPSS: 0.001 (1.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Linux — versions 6.16.1, 6.12.70, 0
- Linux Linux_kernel — versions 6.19
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-23201?
- CVE-2026-23201 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-02-14.
- How severe is CVE-2026-23201?
- Medium severity. CVSS v3 base score is 5.5 out of 10.