{"id":"AZL-94464","summary":"CVE-2026-64580 affecting package kernel for versions less than 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: clear dst.dev on error to avoid double netdev_put in xfrm6_fill_dst()\n\nOn the error path where in6_dev_get(dev) returns NULL, xfrm6_fill_dst()\nreleases the device reference with netdev_put() but leaves\nxdst-\u003eu.dst.dev set. dst_destroy() later calls netdev_put(dst-\u003edev)\nagain, so the same net_device reference is released twice, underflowing\nits refcount (ref_tracker WARNING + \"unregister_netdevice: waiting for\n\u003cdev\u003e to become free\").\n\nClear xdst-\u003eu.dst.dev after the netdev_put(), the same way the XFRM\ndevice-offload paths xfrm_dev_state_add() and xfrm_dev_policy_add() in\nnet/xfrm/xfrm_device.c NULL -\u003edev when releasing the reference on error.\n\n  ref_tracker: reference already released.\n  ref_tracker: allocated in:\n   xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:86)\n   ...\n   udpv6_sendmsg (net/ipv6/udp.c:1696)\n   ...\n  ref_tracker: freed in:\n   xfrm6_fill_dst (net/ipv6/xfrm6_policy.c:90)\n   ...\n  WARNING: lib/ref_tracker.c:322 at ref_tracker_free+0x58b/0x780\n   dst_destroy (net/core/dst.c:115)\n   rcu_core\n   handle_softirqs\n   ...","modified":"2026-08-28T17:48:06.832843822Z","published":"2026-08-05T08:16:38Z","upstream":["CVE-2026-64580"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64580"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-94464.json"}}],"schema_version":"1.9.0"}