DEBIAN-CVE-2026-80906

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    DEBIAN-CVE-2026-80906

    Published: 4 Sept 2026Last Modified: 19 Sept 2026
    Upstream:

    Summary:

    Details: 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 packages

    Package

    Name: linux

    Purl: pkg:deb/debian/linux?arch=source&distro=bookworm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -6.1.187-1

    Affected versions

    6.1.106-1
    6.1.106-2
    6.1.106-3
    6.1.112-1
    6.1.115-1
    6.1.119-1
    6.1.123-1
    6.1.124-1
    6.1.128-1
    6.1.129-1
    6.1.133-1
    6.1.135-1
    6.1.137-1
    6.1.139-1
    6.1.140-1
    6.1.147-1
    6.1.148-1
    6.1.153-1
    6.1.158-1
    6.1.159-1
    6.1.162-1
    6.1.164-1
    6.1.170-1
    6.1.170-2
    6.1.170-3
    6.1.172-1
    6.1.174-1
    6.1.176-1
    6.1.177-1
    6.1.180-1
    6.1.27-1
    6.1.37-1
    6.1.38-1
    6.1.38-2
    6.1.38-2~bpo11+1
    6.1.38-3
    6.1.38-4
    6.1.38-4~bpo11+1
    6.1.52-1
    6.1.55-1
    6.1.55-1~bpo11+1
    6.1.64-1
    6.1.66-1
    6.1.67-1
    6.1.69-1
    6.1.69-1~bpo11+1
    6.1.76-1
    6.1.76-1~bpo11+1
    6.1.82-1
    6.1.85-1
    6.1.90-1
    6.1.90-1~bpo11+1
    6.1.94-1
    6.1.94-1~bpo11+1
    6.1.98-1
    6.1.99-1

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    DEBIAN-CVE-2026-80906 | CVE-DB