Bug 2513356 (CVE-2026-68299) - CVE-2026-68299 kernel: vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Geneve packets
Summary: CVE-2026-68299 kernel: vmxnet3: fix BUG_ON in vmxnet3_get_hdr_len() for Genev...
Keywords:
Status: NEW
Alias: CVE-2026-68299
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-10 12:32 UTC by OSIDB Bzimport
Modified: 2026-08-12 20:13 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2026-08-10 12:32:51 UTC
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.


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