Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: net/sched: ets: clamp quantum in parse and fallback paths ets_qdisc_change() falls back to psched_mtu() with no floor for bands without an explicit quantum. With a crafted size table qdisc_pkt_len reaches ~2 GiB, so a zero psched_mtu on a headerless device makes the deficit-refill loop spin under the qdisc lock. Move the floor into ets_quantum_parse() so explicitly configured quanta are also clamped to [256, 1<<20], not just the fallback path. Conditions to recreate the bug: CONFIG_NET_SCH_ETS=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root ets bands 3 strict 2 quanta 1 1

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• CERT-FR9 Oct 2026CERTFR-2026-AVI-1289

  Multiple vulnerabilities in the Debian LTS Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the Debian LTS Linux kernel. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and denial of service.

  CVE-2025-38237CVE-2025-39833CVE-2025-39925+1311 more CVEs
• CERT-FR2 Oct 2026CERTFR-2026-AVI-1253

  Multiple vulnerabilities in the Debian Linux kernel Translated from French

  Multiple vulnerabilities have been discovered in the Debian Linux kernel. Some of them allow an attacker to cause privilege escalation, a breach of data confidentiality and denial of service.

  CVE-2025-38237CVE-2025-39833CVE-2025-39925+1310 more CVEs
• BSI CERT-Bund24 Sep 2026WID-SEC-2026-3579

  Linux Kernel: Multiple vulnerabilities Translated from German

  CVE-2026-97615CVE-2026-97978CVE-2026-98127+590 more CVEs

[ References ]References

• git.kernel.org/stable/c/1c38487f46b243bfeefec0c0c86023a3904f2214
• git.kernel.org/stable/c/226d2702e74a570f5bfae6115b4706da4b94e5cf
• git.kernel.org/stable/c/440b66cc7b56ea38e9b878ae88da91992efaa4c4
• git.kernel.org/stable/c/4ef8664eafafc8db68a1d52601f17dc008a223b7
• git.kernel.org/stable/c/8b8d782c3b96376217087767dcf662cd3d25f226
• git.kernel.org/stable/c/8f80b113dea0bed3c1a31a4224b72775cd9ec52d
• git.kernel.org/stable/c/99ae477b892e203a37985ebc56f0063e072f7f4b
• git.kernel.org/stable/c/de22c30ec5598aca8797f02082d2ee1358dfa3ff