Junglewise Threat Intelligence

CVE-2024-36929: Linux Kernel denial of service in skbuff fraglist GSO

CVE-2024-36929 · Severity: medium · CVSS 5.5 · Published 2024-05-30

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's networking component could allow a local user to cause a system crash. The issue occurs when the system incorrectly handles specific types of network data packets during internal copying operations. This can lead to a denial-of-service condition, impacting the availability of the affected server or device.

Technical details

A vulnerability exists in the Linux kernel's networking core (net/core/skbuff.c) where SKB_GSO_FRAGLIST skbs are not properly rejected during linearization in skb_copy and skb_copy_expand. If these specific GSO (Generic Segmentation Offload) packets are linearized, they become invalid, leading to a kernel crash during subsequent calls to skb_gso_segment. This is classified as a NULL pointer dereference or general protection fault depending on the kernel state. The fix introduces a check to return NULL early if such an skb is passed to these functions. The vulnerability is reachable by local users with sufficient privileges to trigger these networking paths.

Affected products

  • Linux Linux Kernel 5.6 to 5.10.217, 5.11 to 5.15.159, 5.16 to 6.1.91, 6.2 to 6.6.31, 6.7 to 6.8.10, 6.9-rc1 to 6.9-rc6

Timeline

  • 2024-05-30: advisory: Initial disclosure of CVE-2024-36929
  • 2024-05-17: patched: Fixes committed to various stable kernel branches

References

Related threats