Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: cgroup/dmem: avoid pool UAF An UAF issue was observed: BUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150 Write of size 8 at addr ffff888106715440 by task insmod/527 CPU: 4 UID: 0 PID: 527 Comm: insmod 6.19.0-rc7-next-20260129+ #11 Tainted: [O]=OOT_MODULE Call Trace: <TASK> dump_stack_lvl+0x82/0xd0 kasan_report+0xca/0x100 kasan_check_range+0x39/0x1c0 page_counter_uncharge+0x65/0x150 dmem_cgroup_uncharge+0x1f/0x260 Allocated by task 527: Freed by task 0: The buggy address belongs to the object at ffff888106715400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 64 bytes inside of freed 512-byte region [ffff888106715400, ffff888106715600) The buggy address belongs to the physical page: Memory state around the buggy address: ffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb The issue occurs because a pool can still be held by a caller after its associated memory region is unregistered. The current implementation frees the pool even if users still hold references to it (e.g., before uncharge operations complete). This patch adds a reference counter to each pool, ensuring that a pool is only freed when its reference count drops to zero.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.14, < 6.18.10 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/99a2ef500906138ba58093b9893972a5c303c734Patch
- https://git.kernel.org/stable/c/d3081353acaa6a638dcf75726066ea556a2de8d5Patch
FAQ
What is CVE-2026-23195?
CVE-2026-23195 is a vulnerability with a CVSS score of 7.0 (HIGH). In the Linux kernel, the following vulnerability has been resolved: cgroup/dmem: avoid pool UAF An UAF issue was observed: BUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150 Write ...
How severe is CVE-2026-23195?
CVE-2026-23195 has been rated HIGH with a CVSS base score of 7.0/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-23195?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.