CVE-2026-68299

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc < 667b6e52048eaf4dbcf1707ed87ffd44abb9cb38affected
LinuxLinux45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc < 28cb5d8d13b4c1faf3f688f62e5df82fe7b438d8affected
LinuxLinux45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc < 4fdb0f162ccdbe9626863b10003855703253fa29affected
LinuxLinux45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc < b28596baf87e25a078789f1c05817c8a3bf71257affected
LinuxLinux45dac1d6ea045ae56e4df8d9c70c92c7412bd4fc < 34a71f5361fc3adb5b7138da78750b0d535a8252affected
LinuxLinux4.2affected
LinuxLinux0 < 4.2unaffected
LinuxLinux6.6.148 <= 6.6.*unaffected
LinuxLinux6.12.101 <= 6.12.*unaffected
LinuxLinux6.18.42 <= 6.18.*unaffected
LinuxLinux7.1.6 <= 7.1.*unaffected
LinuxLinux7.2-rc5 <= *unaffected

Weaknesses

References