Improper update of reference count in Linux kernel - CVE-2026-46107
Published: May 29, 2026
Vulnerability identifier: #VU133079
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-46107
CWE-ID: CWE-911
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper reference count handling in the dm-thin rebalance_children function when rebalancing internal btree nodes with a shared child node. A local user can trigger the vulnerable code path to cause a denial of service.
The issue occurs because grandchild node reference counts are not increased when the shared child node is retained, which can lead to "device mapper: space map common: unable to decrement block" errors.
How to mitigate CVE-2026-46107
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/09a65adc7d8bbfce06392cb6d375468e2728ead5
- https://git.kernel.org/stable/c/12161e03d33afce781f68fa11cc6060538862fad
- https://git.kernel.org/stable/c/323d252a4a378834e4fe68298ca61cfc5dd3a460
- https://git.kernel.org/stable/c/5ec0debbcfd43596e32c1239e993de06a704e04c
- https://git.kernel.org/stable/c/85311a585a26640760cd0f3349ab9f2905691044