CVE-2026-68299

Published: August 12, 2026Last modified: August 14, 2026

Description

In the Linux kernel, the following vulnerability has been resolved: vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets vmxnet3_get_hdr_len() assumes gdesc->rcd.v4/v6/tcp always describe the outer header, but for a Geneve-encapsulated packet the device can set them based on the inner header instead, signalled by the VMXNET3_RCD_HDR_INNER_SHIFT bit in the completion descriptor. Since the function never skips the outer encapsulation, this mismatch triggers: - BUG_ON(hdr.ipv4->protocol != IPPROTO_TCP), because the outer protocol is UDP (Geneve), not TCP. - BUG_ON(hdr.eth->h_proto != ...), when the tunnel's outer and inner IP versions differ (e.g. outer IPv6/inner IPv4 or vice versa). Check VMXNET3_RCD_HDR_INNER_SHIFT up front and bail out, since the function cannot locate the inner header it would need to parse. Also convert the remaining BUG_ON()s in this function to return 0 defensively.

Severity score breakdown

ParameterValue
Base score7.5
Attack VectorNETWORK
Attack complexityLOW
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityNONE
Integrity impactNONE
Availability impactHIGH
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Status

ProductReleasePackageStatus
Alpaquita Linux23 LTSlinux-ltsVulnerable (6.1.177-r0)
25 LTSlinux-ltsFixed (6.12.103-r0)
Streamlinux-ltsFixed (6.18.43-r0)

References

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