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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-80906

net: packet: fix wrong transport_header when sending VLAN-tagged frame

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: net: packet: fix wrong transport_header when sending VLAN-tagged frame In packet_parse_headers(), when processing a VLAN-tagged frame, skb_set_network_header() is called to advance network_header past the VLAN tag to the inner protocol header. skb_probe_transport_header() is then called with skb->protocol still set to the outer VLAN EtherType (e.g. ETH_P_8021Q), while nhoff (derived from skb_network_offset()) already points past the VLAN tag to the inner protocol header. In __skb_flow_dissect(), proto is initialized to ETH_P_8021Q and nhoff points past the VLAN tag. When the dissector hits case ETH_P_8021Q, it reads a struct vlan_hdr at nhoff via __skb_header_pointer(), but that offset contains the inner protocol header (e.g. an IP header). The bytes are misinterpreted as a VLAN header, yielding a garbage encapsulated EtherType that matches no known protocol. The dissector returns false, so skb_probe_transport_header() never calls skb_set_transport_header(), leaving transport_header at its uninitialized sentinel value (~0U). Move skb_probe_transport_header() to before skb_set_network_header(). At the time skb_probe_transport_header() is called, network_header still points to the VLAN header, so nhoff correctly points to the VLAN header. The flow dissector can then parse the VLAN header, extract the inner EtherType, and advance nhoff to the inner protocol header, allowing transport_header to be set correctly.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • c2137d565ceb505de69593c181a0543bc4083838 to < a4b82de96d465ddb44bc931145c0fa80c4fe9c9caffected
  • 9ff46c36df2e0a1ac352f2f4038eaf3f0f7361b8 to < fa86bc52ea8ba981f74f851fd61e2a3d3bc0feacaffected
  • dfed913e8b55a0c2c4906f1242fd38fd9a116e49 to < 5479eb9b355f44745d7ccfe112386bd4f96eceeaaffected
  • dfed913e8b55a0c2c4906f1242fd38fd9a116e49 to < e451e20adb869a983a21dda158625f024142e61faffected
  • dfed913e8b55a0c2c4906f1242fd38fd9a116e49 to < 6971cf319263d6a1b4096f9248aca9e57d77a1ebaffected
  • dfed913e8b55a0c2c4906f1242fd38fd9a116e49 to < f9297abbcaba760b7a7b9d63b839f607f738013eaffected
  • dfed913e8b55a0c2c4906f1242fd38fd9a116e49 to < 6386a6ffa2efba2965ed8e4fa303582c0b76a215affected
  • dfed913e8b55a0c2c4906f1242fd38fd9a116e49 to < 01fdecc0480d916c799dbee584833a4a37e94d06affected
  • ad3f90a9c4a2c74bb3711f2031bffda4ec44c849affected
  • 5.10.163 to < 5.10.266affected
  • 5.15.87 to < 5.15.217affected
  • 5.4.229 to < 5.5affected

Linux Linux

Default version status: affected

  • 5.19affected
  • 0 to < 5.19unaffected
  • 5.10.266 to ≤ 5.10.*unaffected
  • 5.15.217 to ≤ 5.15.*unaffected
  • 6.1.184 to ≤ 6.1.*unaffected
  • 6.6.153 to ≤ 6.6.*unaffected
  • 6.12.105 to ≤ 6.12.*unaffected
  • 6.18.46 to ≤ 6.18.*unaffected
  • 7.1.10 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References