Junglewise Threat Intelligence

CVE-2024-27431: Linux Kernel uninitialized memory use in cpumap XDP program

CVE-2024-27431 · Severity: medium · CVSS 5.5 · Published 2024-05-17

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's networking component could allow local users to cause system instability. The issue occurs when the system processes network traffic using a specific high-performance feature called XDP with cpumap. This can lead to the system using uninitialized memory, potentially resulting in unpredictable behavior or a system crash.

Technical details

A 'Use of Uninitialized Resource' vulnerability (CWE-908) exists in the Linux kernel's cpumap component. When an XDP program is attached to a cpumap entry, the xdp_rxq_info structure within the xdp_buff is not initialized. This causes the xdp_md->rx_queue_index value to return random data from uninitialized memory. A local attacker could potentially leverage this to cause a denial of service or observe sensitive memory contents, though the reported impact is primarily on availability. The issue has been resolved by zero-initializing the rxq data structure in kernel/bpf/cpumap.c.

Affected products

  • Linux Linux Kernel versions from 5.9 up to (excluding) 5.10.213; versions from 5.11 up to (excluding) 5.15.152; versions from 5.16 up to (excluding) 6.1.82; versions from 6.2 up to (excluding) 6.6.22; versions from 6.7 up to (excluding) 6.7.10; 6.8-rc1 through 6.8-rc7

Timeline

  • 2024-03-05: patched: Initial fix committed to mainline kernel
  • 2024-05-17: disclosed: CVE published

References

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