SB20261015100 - Excessive Iteration in Linux kernel net

Description

This security bulletin contains information about 1 vulnerability.

1) Excessive Iteration (CVE-ID: CVE-2026-98427)

CWE-ID: CWE-834 - Excessive Iteration

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 excessive iteration in the shared CoDel codel_dequeue() function when processing queued packets with a control-law increment that rounds down to zero or an excessive drop backlog after an idle gap. A local user can generate a UDP flood through an affected queueing configuration to cause a denial of service.

The reported reproducer uses a very small CoDel interval beneath a low-rate token bucket filter on the loopback interface. Packet dropping holds the queueing discipline lock long enough to trigger a kernel soft lockup.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/7f4a5ec6258fd7c92633ec4b0493fc51166d9398
• https://git.kernel.org/stable/c/bacd72289d34d8c05b7de5a12448b87b6dd93878