CVE-2022-49030

What it actually does

Integer overflow when computing the size of the read-only mmap region for ringbuf producer and data pages allows the mapped region to be undersized or wrap, enabling subsequent memory access beyond intended bounds.

Why it matters to the business

Systems relying on eBPF ring buffers for high-volume data collection may experience kernel instability, crashes, or memory corruption that disrupts monitoring, logging, and security tooling.

How an attack unfolds

An attacker supplies a ringbuf map with max_entries near 2 GB to a 32-bit userspace application running on a 64-bit kernel; libbpf performs the mmap without checking for size_t or u32 overflow, resulting in an undersized mapping that later writes or reads beyond the allocated region.

How to fix it

Update the Linux kernel to a version containing commit 8a549ab6724520aa3c07f47e0eba820293551490 or later; rebuild and redeploy any applications that statically link libbpf with the corrected ringbuf mmap logic.

How to confirm the fix worked

Confirm the running kernel contains the referenced commit or a backport that casts the mmap size to __u64 and performs an overflow check before calling mmap; test ringbuf creation with max_entries = 0x7FFFFFFF on both 64-bit and 32-bit-on-64-bit configurations.

Typical attack path

1. Identify or deploy a program that creates a ringbuf map via libbpf
2. Set max_entries to a value that triggers u32 or size_t overflow on the target architecture
3. Trigger the mmap path inside libbpf
4. Perform subsequent ringbuf operations that write past the truncated mapping

How to detect it

Review kernel logs for ringbuf mmap failures or size-related warnings around libbpf initialization; examine auditd or syscall traces for unusual mmap calls with sizes near 2 GB originating from processes using eBPF.

What your security team should do

• Prioritize kernel upgrades on all hosts that run libbpf-based workloads
• Audit custom eBPF programs for direct use of ringbuf maps and ensure they are rebuilt against fixed libbpf
• Monitor EPSS and KEV feeds for any future change in exploitability