high CVSS 7.8 EPSS <0.1%

CVE-2022-49030·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: libbpf: Handle size overflow for ringbuf mmap The maximum size of ringbuf is 2GB on x86-64 host, so 2 * max_entries will overflow u32 when mapping producer page and data pages. Only casting max_entries to size_t is not enough, because for 32-bits application on 64-bits kernel the size of read-only mmap region also could overflow size_t. So fixing it by casting the size of read-only mmap region into a __u64 and checking whether or not there will be overflow during mmap.

Severity
high
Software
Kernel
Fixed in
6.0.12
Published

How likely is exploitation

FIRST's Exploit Prediction Scoring System puts the probability of this CVE being exploited in the next 30 days at <0.1% — higher than 4% of all published CVEs. EPSS is an independent forecast of exploitation, not a severity rating: it says nothing about how much damage a successful attack does, which is what a CVSS score measures.

Read the two together. CVE-2022-49030 scores 7.8 on CVSS, so a successful attack would be serious — but at <0.1%, almost nobody is currently attempting it. That is a different situation from a flaw under mass exploitation, and it is usually the difference between patching on your next maintenance window and patching tonight.

Affected versions

From: 5.16

Until: 6.0.12

Fixed in: 6.0.12

How to fix this CVE

Update your Linux kernel to version 6.0.12 or later to patch a critical memory mapping vulnerability in the eBPF ringbuf implementation. This issue affects kernel versions 5.16 through 6.0.11 and can be exploited by local users with limited privileges to trigger memory corruption. Apply the kernel update immediately, then reboot your system to activate the patched version.

sudo dnf update kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check your current kernel version with: uname -r
  2. Step 2: Verify if libbpf is in use by checking: dpkg -l | grep libbpf (Debian/Ubuntu) or rpm -qa | grep libbpf (RHEL/CentOS)
  3. Step 3: Review kernel logs for memory-related errors during eBPF operations: sudo dmesg | grep -i 'bpf\|ringbuf\|mmap'
  4. Step 4: After applying patches, confirm the new version with: uname -r and verify it's 6.0.12 or later

FAQ

What is CVE-2022-49030?

CVE-2022-49030 is an integer overflow vulnerability in the Linux kernel's eBPF ringbuf memory mapping code that allows local attackers with limited privileges to cause memory corruption through crafted ringbuf operations.

Is CVE-2022-49030 being actively exploited?

No, this vulnerability is not currently listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, and no public exploits have been disclosed.

What versions of Kernel are affected by CVE-2022-49030?

Linux kernel versions 5.16 through 6.0.11 are affected; version 6.0.12 and later contain the fix.

How do I check if my server is vulnerable to CVE-2022-49030?

Run 'uname -r' to display your kernel version. If it shows any version between 5.16 and 6.0.11, your system is vulnerable. Compare against your kernel release notes to confirm exact version.

Does Defensia detect CVE-2022-49030?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Linux kernel is installed on a monitored server, CVE-2022-49030 will appear in your dashboard with remediation steps.

Related Kernel CVEs

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CVE-2026-53228CVSS 9.8In the Linux kernel, the following vulnerability has been resolved: ipv6: sit: reload inner IPv6 header after GSO offloads ipip6_tunnel_xmit() caches the inner IPv6 header pointer at function entry and continues using it after iptunnel_handle_offloads(). For GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone(). When the skb header is cloned, skb_header_unclone() can call pskb_expand_head(), which may move the skb head. The pskb_expand_head() contract requires pointers into the skb header to be reloaded after the call. If the later skb_realloc_headroom() branch is not taken, SIT uses the stale iph6 pointer to read the inner hop limit and DS field. That can read from a freed skb head after the old head's remaining clone is released. Reload iph6 after the offload helper succeeds and before subsequent reads from the inner IPv6 header. Keep the existing reload after skb_realloc_headroom(), since that branch can also replace the skb.

References

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