CVE-2026-64055
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk41th percentile - higher than 41% of all known CVEs
Summary
In the Linux kernel, a vulnerability was found in the Cortina Ethernet driver where the fragment counter (frag_nr) is reset during packet reception in the gmac_rx() function. When the ring buffer is completely emptied during a poll cycle, the fragment counter is reset even though the packet is not yet fully assembled in the SKB, potentially causing incorrect packet reassembly.
Risk Assessment
This vulnerability may cause incorrect network packet reassembly, leading to data loss, transmission errors, or potential denial of service (DoS) attacks on systems using this driver.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit that carries over the fragment counter in the port structure). Monitor for patches from your system distributor.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net: ethernet: cortina: Carry over frag counter The gmac_rx() NAPI poll function assembles packets in an SKB from a ring buffer. If the ring buffer gets completely emptied during a poll cycle, we exit gmac_rx(), but the packet is not yet completely assembled in the SKB, yet the fragment counter frag_nr is reset to zero on the next invocation. Solve this by making the RX fragment counter a part of the port struct, and carry it over between invocations. Reset the fragment counter only right after calling napi_gro_frags(), on error (after calling napi_free_frags()) or if stopping the port. Reset it in some place where not strictly necessary just to emphasize what is going on. This was found by Sashiko during normal patch review.