high CVSS 7.1

CVE-2024-50123·Kernel vulnerability

In the Linux kernel, the following vulnerability has been resolved: bpf: Add the missing BPF_LINK_TYPE invocation for sockmap There is an out-of-bounds read in bpf_link_show_fdinfo() for the sockmap link fd. Fix it by adding the missing BPF_LINK_TYPE invocation for sockmap link Also add comments for bpf_link_type to prevent missing updates in the future.

Severity
high
Software
Kernel
Fixed in
6.11.6
Published
2024-11-05

Affected versions

From: 6.10

Until: 6.11.6

Fixed in: 6.11.6

How to fix this CVE

Update your Linux kernel to version 6.11.6 or later to patch an out-of-bounds read vulnerability in the BPF subsystem's sockmap link handling. This memory safety issue could allow a local, unprivileged user to trigger a kernel crash or potentially leak sensitive kernel memory. Perform a kernel update and reboot your system to apply the fix.

sudo dnf upgrade kernel kernel-devel && sudo reboot

Defensia detects this vulnerability

How to check if you are affected

  1. Step 1: Check kernel version with `uname -r` and compare against 6.11.6 — versions 6.10 through 6.11.5 are vulnerable
  2. Step 2: Verify if BPF and sockmap modules are loaded with `grep -E 'bpf|sockmap' /proc/modules` — if absent, exposure is lower but kernel should still be updated
  3. Step 3: Search kernel logs for out-of-bounds read warnings with `journalctl -xe | grep -i 'out.of.bounds\|bpf_link_show_fdinfo\|sockmap' | tail -20`
  4. Step 4: After updating, confirm the new kernel version is running with `uname -r` and ensure it shows 6.11.6 or higher

FAQ

What is CVE-2024-50123?

CVE-2024-50123 is a memory safety vulnerability in the Linux kernel's BPF (Berkeley Packet Filter) subsystem where the sockmap link type was missing proper enumeration handling, causing out-of-bounds reads when user-space applications query file descriptor information. A local attacker with user privileges could trigger this to crash the kernel or read privileged memory.

Is CVE-2024-50123 being actively exploited?

No, CVE-2024-50123 is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog and no public exploits are currently available, though the low attack complexity and local attack vector mean patches should be applied promptly.

What versions of Kernel are affected by CVE-2024-50123?

Linux kernel versions 6.10 through 6.11.5 are affected. Kernel 6.11.6 and later versions contain the fix.

How do I check if my server is vulnerable to CVE-2024-50123?

Run `uname -r` to see your kernel version. If it shows 6.10 or 6.11.x (where x is less than 6), your system is vulnerable and requires immediate patching.

Does Defensia detect CVE-2024-50123?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Kernel is installed on a monitored server, CVE-2024-50123 will appear in your dashboard with remediation steps.

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References

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