The vulnerability arises from removing the napi_synchronize() call in the igb driver’s down routine without properly sequencing NAPI disable and queue removal. When an AF_XDP zero‑copy application is killed abruptly, the XSK buffer pool is released while NAPI polling continues. Because the driver never clears the NAPI_STATE_SCHED flag, igb_down blocks indefinitely and the TX watchdog triggers, leaving the network transmit queue permanently stalled. This results in a denial of service on the affected network interface.

All Linux kernels that ship the igb network driver are affected. The fix has been incorporated into recent stable releases; until the patch is applied, any distribution using a version of the kernel that still contains the old down path is vulnerable. No specific version numbers are listed, so systems should verify whether they contain commit 27f5997686ee7fb7ac01be72b2010f168a3409fc or later.

The CVSS score of 5.5 indicates a moderate severity. Because exploitation requires a local user to bring down the interface by abruptly terminating an AF_XDP application, the attack vector is local and contingent on sufficient privileges. The EPSS score is < 1%, indicating a very low exploitation probability, and the vulnerability is not listed in the CISA KEV catalog. Attackers with local access can use the described sequence to cause a service interruption; remote exploitation is not indicated.