CVE-2026-64055

net: ethernet: cortina: Carry over frag counter

State: Published
Severity: 9.8 Critical
Published: Jul 19, 2026
Updated: Aug 5, 2026
Reserved: Jul 19, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	9.8 Critical	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before df31e3b64455293df1ea89c7da7d5c9bfbcdd253Affected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 7af1fabdee744b7995fe01b30b77dfc397657cb5Affected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 75105fcf73f1ce7d9f769aaefec6e6d6645d5ac0Affected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 78cf08b3be47c28f07008a76c932bad7cdffa9d8Affected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 7123cf481e21b54eb6adc4cb0d8dc2876aeaee41Affected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before c373b34877afea61c89e0dd2e38948c624249b9bAffected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 46806096f35b8d3dfa2f321ddd77f597edcdb85fAffected 4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before ebd8ec2b309e3a447851b456ccaf8fb39f3661e7Affected
LinuxLinux	4.16Affected before 4.16Not affected 5.10.258 through 5.10.Not affected 5.15.209 through 5.15.Not affected 6.1.175 through 6.1.Not affected 6.6.142 through 6.6.Not affected 6.12.92 through 6.12.Not affected 6.18.34 through 6.18.Not affected 7.0.11 through 7.0.*Not affected 7.1 and laterNot affected

Product

Versions

LinuxLinux

4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before df31e3b64455293df1ea89c7da7d5c9bfbcdd253Affected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 7af1fabdee744b7995fe01b30b77dfc397657cb5Affected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 75105fcf73f1ce7d9f769aaefec6e6d6645d5ac0Affected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 78cf08b3be47c28f07008a76c932bad7cdffa9d8Affected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 7123cf481e21b54eb6adc4cb0d8dc2876aeaee41Affected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before c373b34877afea61c89e0dd2e38948c624249b9bAffected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before 46806096f35b8d3dfa2f321ddd77f597edcdb85fAffected
4d5ae32f5e1e13f7f36d6439ec3257993b9f5b88 to before ebd8ec2b309e3a447851b456ccaf8fb39f3661e7Affected

LinuxLinux

4.16Affected
before 4.16Not affected
5.10.258 through 5.10.*Not affected
5.15.209 through 5.15.*Not affected
6.1.175 through 6.1.*Not affected
6.6.142 through 6.6.*Not affected
6.12.92 through 6.12.*Not affected
6.18.34 through 6.18.*Not affected
7.0.11 through 7.0.*Not affected
7.1 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.