Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
bpf: Add bpf_prog_run_data_pointers()
syzbot found that cls_bpf_classify() is able to change tc_skb_cb(skb)->drop_reason triggering a warning in sk_skb_reason_drop().
WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 __sk_skb_reason_drop net/core/skbuff.c:1189 [inline] WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 sk_skb_reason_drop+0x76/0x170 net/core/skbuff.c:1214
struct tc_skb_cb has been added in commit ec624fe740b4 (“net/sched: Extend qdisc control block with tc control block”), which added a wrong interaction with db58ba459202 (“bpf: wire in data and data_end for cls_act_bpf”).
drop_reason was added later.
Add bpf_prog_run_data_pointers() helper to save/restore the net_sched storage colliding with BPF data_meta/data_end.
Details
- Affected product:
- Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | Released |
32 kernels
|
| Debian 13 | Will Not Fix | — |
| Oracle Linux 8 UEK 7 | Planned | — |
| Oracle Linux 9 UEK 7 | Planned | — |
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
57 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
40 kernels
|
| Ubuntu 22.04 | Released |
90 kernels
|
| Ubuntu 22.04 AWS | Released |
81 kernels
|
| Ubuntu 22.04 Azure | Released |
73 kernels
|
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |