fprobe: Fix unregister_fprobe() to wait for RCU grace period
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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
- 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: fprobe: Fix unregister_fprobe() to wait for RCU grace period Commit 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") changed fprobe to register struct fprobe to an rcu-hlist, but it forgot to wait for RCU GP. Thus there can be use-after-free if the fprobe is released right after unregistering. This can be happened on fprobe event and sample module code. To fix this issue, add synchronize_rcu() in unregister_fprobe(). Note that BPF is OK because fprobe is used as a part of bpf_kprobe_multi_link. This unregisters its fprobe in bpf_kprobe_multi_link_release() and it is deallocated via bpf_kprobe_multi_link_dealloc(), which is invoked from bpf_link_defer_dealloc_rcu_gp() RCU callback. For BPF, this also introduced unregister_fprobe_async() which does NOT wait for RCU grace priod.
Timeline
- CVE published
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
6.14