In the Linux kernel, the following vulnerability has been resolved: net: ethernet: cortina: Carry over frag counter The gmac_rx() NAPI poll function… (CVE-2026-64055)
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.
AI Analysis
Technical Summary
The Linux kernel vulnerability CVE-2026-64055 affects the ethernet cortina driver in the gmac_rx() NAPI poll function. During packet assembly from a ring buffer, if the buffer empties mid-cycle, the fragment counter (frag_nr) resets to zero on the next invocation before the packet is fully assembled. This improper reset could cause incomplete or corrupted packet assembly. The patch moves the fragment counter into the port structure to preserve its state across invocations and resets it only after successful fragment processing, error handling, or port stopping.
Potential Impact
Improper handling of the fragment counter during packet assembly could lead to incomplete or corrupted network packets being processed by the kernel. This may affect network reliability or stability on systems using the affected ethernet cortina driver. No known exploits are reported in the wild.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by modifying the fragment counter handling in the ethernet cortina driver. Users should update to a kernel version that includes this patch once available. Patch status is not explicitly confirmed in the provided data; check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply the update accordingly.
In the Linux kernel, the following vulnerability has been resolved: net: ethernet: cortina: Carry over frag counter The gmac_rx() NAPI poll function… (CVE-2026-64055)
Description
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.
CVSS v3.1
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel vulnerability CVE-2026-64055 affects the ethernet cortina driver in the gmac_rx() NAPI poll function. During packet assembly from a ring buffer, if the buffer empties mid-cycle, the fragment counter (frag_nr) resets to zero on the next invocation before the packet is fully assembled. This improper reset could cause incomplete or corrupted packet assembly. The patch moves the fragment counter into the port structure to preserve its state across invocations and resets it only after successful fragment processing, error handling, or port stopping.
Potential Impact
Improper handling of the fragment counter during packet assembly could lead to incomplete or corrupted network packets being processed by the kernel. This may affect network reliability or stability on systems using the affected ethernet cortina driver. No known exploits are reported in the wild.
Mitigation Recommendations
A fix has been implemented in the Linux kernel to address this vulnerability by modifying the fragment counter handling in the ethernet cortina driver. Users should update to a kernel version that includes this patch once available. Patch status is not explicitly confirmed in the provided data; check the official Linux kernel advisories or vendor updates for the exact fixed versions and apply the update accordingly.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-j6pg-f87q-4363
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-64055"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27a92a4a8d598912cb9a
Added to database: 07/19/2026, 19:38:17 UTC
Last enriched: 07/19/2026, 19:54:57 UTC
Last updated: 07/20/2026, 20:27:30 UTC
Views: 12
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