Junglewise Threat Intelligence

CVE-2026-43173: Linux Kernel NULL pointer dereference in IXP4xx Ethernet driver

CVE-2026-43173 · Severity: medium · CVSS 5.5 · Published 2026-05-06

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's network driver for XScale hardware could allow a local user to crash the system. The issue occurs when certain network diagnostic tools, like tcpdump, attempt to access time-stamping features on hardware that does not support them. This results in a system 'splat' or kernel crash, potentially disrupting operations and service availability.

Technical details

A NULL pointer dereference exists in the ixp4xx_eth driver within the Linux kernel. The function ixp46x_ptp_find() was being called unconditionally in ixp4xx_get_ts_info(), even on hardware variants (other than ixp46x) that do not support Precision Time Protocol (PTP). When a local user executes tools like tcpdump that trigger ethtool ioctl calls to retrieve timestamping information, the kernel attempts to access uninitialized PTP clock structures, resulting in a kernel panic. The fix introduces a proper check for ixp46x CPU support within the PTP discovery logic. Patches have been released across multiple stable kernel branches.

Affected products

  • Linux Linux Kernel 5.15 to 5.15.202, 5.16 to 6.1.165, 6.2 to 6.6.128, 6.7 to 6.12.75, 6.13 to 6.18.16, 6.19 to 6.19.6

Timeline

  • 2026-05-06: disclosed: Initial disclosure of the vulnerability
  • 2026-05-06: advisory: NVD advisory published
  • 2026-02-19: patched: Fix authored by Linus Walleij

References

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