Use-after-free in Linux kernel - CVE-2026-45949

Vulnerability identifier: #VU132538

CSH Severity: Low

CVSS v4 BT: 4.3 [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-2026-45949

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in the hwrng core when unregistering and registering hardware random number generator devices concurrently. A local user can trigger repeated register and unregister operations to cause a denial of service.

The issue is caused by a race condition involving the global hwrng_fill pointer and thread lifecycle handling.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-extra-modules
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 6.6.0-145.3.15.146
bpftool - update to 6.6.0-145.3.15.146
bpftool-debuginfo - update to 6.6.0-145.3.15.146
kernel-debuginfo - update to 6.6.0-145.3.15.146
kernel-debugsource - update to 6.6.0-145.3.15.146
kernel-devel - update to 6.6.0-145.3.15.146
kernel-extra-modules - update to 6.6.0-145.3.15.146
kernel-headers - update to 6.6.0-145.3.15.146
kernel-source - update to 6.6.0-145.3.15.146
kernel-tools - update to 6.6.0-145.3.15.146
kernel-tools-debuginfo - update to 6.6.0-145.3.15.146
kernel-tools-devel - update to 6.6.0-145.3.15.146
perf - update to 6.6.0-145.3.15.146
perf-debuginfo - update to 6.6.0-145.3.15.146
python3-perf - update to 6.6.0-145.3.15.146
python3-perf-debuginfo - update to 6.6.0-145.3.15.146

• https://git.kernel.org/stable/c/ad38f2cdfef9a2f2899c30cad269baec5bfd4a5d
• https://git.kernel.org/stable/c/cc2f39d6ac48e6e3cb2d6240bc0d6df839dd0828
• https://git.kernel.org/stable/c/d5b7730f06994499632026c30e38e0317c4569e2
• https://git.kernel.org/stable/c/dcf416eb88eafe1e3c0f920a14bdffd10bc4d259

• Use-after-free in Linux kernel hwrng core
• openEuler 24.03 LTS SP3 update for kernel