High · published September 6, 2023
A use-after-free vulnerability in the Linux kernel's net/sched: sch_hfsc (HFSC qdisc traffic control) component can be exploited to achieve local privilege escalation.
If a class with a link-sharing curve (i.e. with the HFSC_FSC flag set) has a parent without a link-sharing curve, then init_vf() will call vttree_insert() on the parent, but vttree_remove() will be skipped in update_vf(). This leaves a dangling pointer that can cause a use-after-free.
We recommend upgrading past commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 2.6.12, < 4.14.327 | 4.14.327 |
| linux/linux_kernel | ≥ 4.15, < 4.19.295 | 4.19.295 |
| linux/linux_kernel | ≥ 4.20, < 5.4.257 | 5.4.257 |
| linux/linux_kernel | ≥ 5.5, < 5.10.195 | 5.10.195 |
| linux/linux_kernel | ≥ 5.11, < 5.15.132 | 5.15.132 |
| linux/linux_kernel | ≥ 5.16, < 6.1.53 | 6.1.53 |
| linux/linux_kernel | ≥ 6.2, < 6.4.16 | 6.4.16 |
| linux/linux_kernel | ≥ 6.5, < 6.5.3 | 6.5.3 |
| debian/debian_linux | all versions | — |