CVE-2026-74744Memory corruption in Linux kernel ipvlan module
In the Linux kernel, the following vulnerability has been resolved: ipvlan: inherit needed_headroom and needed_tailroom from phy_dev ipvlan devices inherit hard_header_len from phy_dev during ipvlan_init(), but leave needed_headroom and needed_tailroom set to 0. When the underlying phy_dev (or stacked lower device) requires extra headroom or tailroom for headers/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx headroom), upper layers calculating packet headroom and tailroom fail to reserve sufficient space. This can result in reallocation overhead, skb headroom underflows, or KASAN slab-use-after-free crashes when dev_hard_header() / ipvlan_hard_header() prepends header data or when lower devices append tailroom. Fix this by: 1. Inheriting needed_headroom and needed_tailroom from phy_dev in ipvlan_init(). 2. Propagating needed_headroom and needed_tailroom updates to attached ipvlans in ipvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.
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Vulnerabilidad critica en el kernel de Linux (modulo ipvlan) que puede provocar corrupcion de memoria (use-after-free). El fallo ocurre al procesar paquetes en configuraciones que usan ipvlan sobre tuneles como WireGuard o IPsec, pudiendo comprometer la estabilidad o seguridad del sistema.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HEPSS
No EPSS score yet (CVE may be too fresh).
Technical description
In the Linux kernel, the following vulnerability has been resolved: ipvlan: inherit needed_headroom and needed_tailroom from phy_dev ipvlan devices inherit hard_header_len from phy_dev during ipvlan_init(), but leave needed_headroom and needed_tailroom set to 0. When the underlying phy_dev (or stacked lower device) requires extra headroom or tailroom for headers/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx headroom), upper layers calculating packet headroom and tailroom fail to reserve sufficient space. This can result in reallocation overhead, skb headroom underflows, or KASAN slab-use-after-free crashes when dev_hard_header() / ipvlan_hard_header() prepends header data or when lower devices append tailroom. Fix this by: 1. Inheriting needed_headroom and needed_tailroom from phy_dev in ipvlan_init(). 2. Propagating needed_headroom and needed_tailroom updates to attached ipvlans in ipvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.
References
- https://git.kernel.org/stable/c/5c2ca77212eb38559b0353b8363b7a84f4b019dd
- https://git.kernel.org/stable/c/5f33188457bbcc1b11ca87084037963c516ed3d9
- https://git.kernel.org/stable/c/af602c4d0ee548da18e2409b4b4da1079625a372
- https://git.kernel.org/stable/c/c0fbe31f6b20ade0465130685859faa5c86fda59
- https://git.kernel.org/stable/c/e16e960d55a40d36bd7c2494cc005e757dc9a1ef
- https://git.kernel.org/stable/c/f3c17ff65f54781cde696e16a6c577615ed735aa