CVE-2026-68142

Summary

In the Linux kernel, the following vulnerability has been resolved:

geneve: require CAP_NET_ADMIN in the device netns for changelink

A tunnel changelink() operates on at most two netns, dev_net(dev) and the sticky underlay netns geneve->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in geneve->net can rewrite a geneve device whose underlay lives in geneve->net.

geneve_changelink() applies the new configuration against geneve->net: geneve_link_config() and the geneve_quiesce()/geneve_unquiesce() pair reopen the underlay sockets in that netns (geneve_sock_add() uses geneve->net), so the same reasoning as the tunnel changelink series applies here.

Gate geneve_changelink() with rtnl_dev_link_net_capable(), at the top of the op before any attribute is parsed, matching ipgre_changelink() and the rest of the "require CAP_NET_ADMIN in the device netns for changelink" series.

Found by 0sec automated security-research tooling (https://0sec.ai).

Affected Software

VendorProductVersion RangeStatus
LinuxLinux5b861f6baa3a22a48d7a4ad0ce38a223d36c978a < 2abdacc927c92fa6a9cc8341e8c9b88dcb561553affected
LinuxLinux5b861f6baa3a22a48d7a4ad0ce38a223d36c978a < 9de5518fc1fab583526a8f66b8e505c4864dc60aaffected
LinuxLinux5b861f6baa3a22a48d7a4ad0ce38a223d36c978a < f8c498585d2a08aa623748353c3e61467b7e9fd2affected
LinuxLinux5b861f6baa3a22a48d7a4ad0ce38a223d36c978a < 95f45e20f1b2cec13823f0f68060ab4b2261b2c1affected
LinuxLinux5b861f6baa3a22a48d7a4ad0ce38a223d36c978a < 8efb8f8bbb353b8f2fdf4f37534c6d96c9f69e01affected
LinuxLinux4.14affected
LinuxLinux0 < 4.14unaffected
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