Updated: 2025-12-28 03:41:10.700628
Description:
In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: fix a potential crash on gso_skb handling SFQ has an assumption of always being able to queue at least one packet. However, after the blamed commit, sch->q.len can be inflated by packets in sch->gso_skb, and an enqueue() on an empty SFQ qdisc can be followed by an immediate drop. Fix sfq_drop() to properly clear q->tail in this situation. ip netns add lb ip link add dev to-lb type veth peer name in-lb netns lb ethtool -K to-lb tso off # force qdisc to requeue gso_skb ip netns exec lb ethtool -K in-lb gro on # enable NAPI ip link set dev to-lb up ip -netns lb link set dev in-lb up ip addr add dev to-lb 192.168.20.1/24 ip -netns lb addr add dev in-lb 192.168.20.2/24 tc qdisc replace dev to-lb root sfq limit 100 ip netns exec lb netserver netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 &
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | MEDIUM | 5.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Needs Triage | 2025-12-28 08:02:22 | ||
| CentOS 8.4 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:08:26 | This flaw only affects the SFQ queuing discipline under specific, non-default networking conditions ... | |
| CentOS 8.5 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:08:27 | This flaw only affects the SFQ queuing discipline under specific, non-default networking conditions ... | |
| CentOS Stream 8 ELS | kernel | 4.18.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:08:25 | This flaw only affects the SFQ queuing discipline under specific, non-default networking conditions ... | |
| Oracle Linux 7 ELS | kernel-uek | 5.4.17 | 5.5 | MEDIUM | Released | CLSA-2025:1757963029 | 2025-09-16 11:20:01 | |
| TuxCare 9.6 ESU | kernel | 5.14.0 | 5.5 | MEDIUM | Needs Triage | 2025-12-28 08:02:21 | ||
| Ubuntu 20.04 ELS | linux | 5.4.0 | 5.5 | MEDIUM | Ignored | 2026-01-17 01:14:51 | This flaw only affects the SFQ queuing discipline under specific, non-default networking conditions ... |