bpf: Fix sleepable check for tracing/lsm prog
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 7.2.6
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 16d9c5660692d6f0e6aba367274de2b6dfd4343c · fixed in 976f1be72740cfbc351d3841fd21186dda3ea723; From 16d9c5660692d6f0e6aba367274de2b6dfd4343c · fixed in 00244bdaa423d93f4571f3f6854378ce3365e524
- Linux Linux
7.1
- KernelLinux
From 7.1.0 · fixed in 7.2.6