{"id":"AZL-89675","summary":"CVE-2026-46321 affecting package kernel for versions less than 6.6.143.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntun: free page on short-frame rejection in tun_xdp_one()\n\ntun_xdp_one() returns -EINVAL on a frame shorter than ETH_HLEN without\nfreeing the page that vhost_net_build_xdp() allocated for it.\ntun_sendmsg() discards that -EINVAL and still returns total_len, so\nvhost_tx_batch() takes the success path and never frees the page; each\nshort frame in a batch leaks one page-frag chunk.\n\nA local process that can open /dev/net/tun and /dev/vhost-net can hit\nthis path: it attaches a tun/tap device as the vhost-net backend and\nfeeds TX descriptors whose length minus the virtio-net header is below\nETH_HLEN. Each kick leaks the page-frag chunks for that batch, and a\ntight submission loop exhausts host memory and triggers an OOM panic.\nFree the page before returning -EINVAL, matching the XDP-program error\npath in the same function.","modified":"2026-08-28T17:48:10.879826288Z","published":"2026-06-09T13:16:37Z","upstream":["CVE-2026-46321"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46321"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.143.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-89675.json"}}],"schema_version":"1.9.0"}