SB20260812399 - Race condition in Linux kernel sched

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-68138)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 6.8 [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]

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

The vulnerability exists due to a race condition leading to use-after-free and double-free in qdisc_get_rtab() and qdisc_put_rtab() when processing concurrent RTM_NEWTFILTER requests that add flower filters with a police action carrying the same rate. A local user can send concurrent netlink filter configuration requests to cause a denial of service.

The corrupted qdisc_rate_table object is shared system-wide because the affected rate-table list is process-global rather than per-network-namespace.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/f43ee0c0730d6191629b5ee1ceae27b1ebfdc047
• https://git.kernel.org/stable/c/fb29e1b41052488ee3f2d115d4a870497ebd7f7d