Updated: 2026-02-27 02:23:51.810341
Description:
In the Linux kernel, the following vulnerability has been resolved: sch/netem: fix use after free in netem_dequeue If netem_dequeue() enqueues packet to inner qdisc and that qdisc returns __NET_XMIT_STOLEN. The packet is dropped but qdisc_tree_reduce_backlog() is not called to update the parent's q.qlen, leading to the similar use-after-free as Commit e04991a48dbaf382 ("netem: fix return value if duplicate enqueue fails") Commands to trigger KASAN UaF: ip link add type dummy ip link set lo up ip link set dummy0 up tc qdisc add dev lo parent root handle 1: drr tc filter add dev lo parent 1: basic classid 1:1 tc class add dev lo classid 1:1 drr tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2: handle 3: drr tc filter add dev lo parent 3: basic classid 3:1 action mirred egress redirect dev dummy0 tc class add dev lo classid 3:1 drr ping -c1 -W0.01 localhost # Trigger bug tc class del dev lo classid 1:1 tc class add dev lo classid 1:1 drr ping -c1 -W0.01 localhost # UaF
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | HIGH | 7.8 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | kernel | 5.14.0 | 7.8 | HIGH | Released | CLSA-2025:1743193221 | 2024-10-21 17:30:27 | |
| CentOS 7 ELS | kernel | 3.10.0 | 7.8 | HIGH | Released | CLSA-2024:1727692412 | 2024-10-14 17:32:58 | |
| CentOS 8.4 ELS | kernel | 4.18.0 | 7.8 | HIGH | Released | CLSA-2024:1727690947 | 2024-09-30 10:48:06 | |
| CentOS 8.5 ELS | kernel | 4.18.0 | 7.8 | HIGH | Released | CLSA-2024:1727690025 | 2024-09-30 10:48:07 | |
| CentOS Stream 8 ELS | kernel | 4.18.0 | 7.8 | HIGH | Released | CLSA-2024:1729874131 | 2024-10-25 14:32:56 | |
| CloudLinux 7 ELS | kernel | 3.10.0 | 7.8 | HIGH | Ignored | 2025-01-10 22:43:35 | CloudLinux 6 and 7 support is limited and provided on demand. We strongly recommend upgrading to Clo... | |
| Oracle Linux 7 ELS | kernel | 3.10.0 | 7.8 | HIGH | Released | CLSA-2025:1742322442 | 2025-03-25 03:29:34 | |
| Oracle Linux 7 ELS | kernel-uek | 5.4.17 | 7.8 | HIGH | Already Fixed | 2026-02-04 01:40:54 | ||
| RHEL 7 ELS | kernel | 3.10.0 | 7.8 | HIGH | Released | CLSA-2025:1750353839 | 2025-06-20 04:47:11 | |
| Ubuntu 16.04 ELS | linux-hwe | 4.15.0 | 7.8 | HIGH | Released | CLSA-2024:1728584752 | 2024-10-10 14:29:03 |