Description
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix sleepable check for tracing/lsm prog
When CONFIG_FUNCTION_ERROR_INJECTION is disabled, a sleepable tracing prog is allowed to attach to '__x64_'-alike prefix symbols.
It is because the verifier does not verify whether the symbol is a kernel function or a bpf prog. That said, a sleepable tracing prog is allowed to attach to a bpf prog target whose name has '__x64_'-alike prefix.
For example, a sleepable fentry prog attaches to a '__x64_sys_nop' XDP prog, and copies buffer from a user pointer with bpf_copy_from_user() helper. After attaching the XDP prog to lo interface, the kernel BUG could be triggered by 'ping -c 1 -W 1 127.0.0.1':
[ 3.460756] BUG: sleeping function called from invalid context at kernel/bpf/trampoline.c:1324
Fix it by disallowing sleepable prog always when its target btf is not a kernel's btf.
Metrics
No CVSS score has been published yet.
Affected software
Source: the vendor's advisory (CNA). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= 16d9c5660692d6f0e6aba367274de2b6dfd4343c, < 976f1be72740cfbc351d3841fd21186dda3ea723; >= 16d9c5660692d6f0e6aba367274de2b6dfd4343c, < 00244bdaa423d93f4571f3f6854378ce3365e524 |
| Linux | Linux | 7.1 |
References
Timeline
- Published
- Sep 17, 2026
- Last modified
- Oct 19, 2026
- NVD status
- Received