{"id":"AZL-73081","summary":"CVE-2025-68366 affecting package kernel for versions less than 6.6.121.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnbd: defer config unlock in nbd_genl_connect\n\nThere is one use-after-free warning when running NBD_CMD_CONNECT and\nNBD_CLEAR_SOCK:\n\nnbd_genl_connect\n  nbd_alloc_and_init_config // config_refs=1\n  nbd_start_device // config_refs=2\n  set NBD_RT_HAS_CONFIG_REF\t\t\topen nbd // config_refs=3\n  recv_work done // config_refs=2\n\t\t\t\t\t\tNBD_CLEAR_SOCK // config_refs=1\n\t\t\t\t\t\tclose nbd // config_refs=0\n  refcount_inc -\u003e uaf\n\n------------[ cut here ]------------\nrefcount_t: addition on 0; use-after-free.\nWARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290\n nbd_genl_connect+0x16d0/0x1ab0\n genl_family_rcv_msg_doit+0x1f3/0x310\n genl_rcv_msg+0x44a/0x790\n\nThe issue can be easily reproduced by adding a small delay before\nrefcount_inc(&nbd-\u003econfig_refs) in nbd_genl_connect():\n\n        mutex_unlock(&nbd-\u003econfig_lock);\n        if (!ret) {\n                set_bit(NBD_RT_HAS_CONFIG_REF, &config-\u003eruntime_flags);\n+               printk(\"before sleep\\n\");\n+               mdelay(5 * 1000);\n+               printk(\"after sleep\\n\");\n                refcount_inc(&nbd-\u003econfig_refs);\n                nbd_connect_reply(info, nbd-\u003eindex);\n        }","modified":"2026-04-01T05:22:35.912651Z","published":"2025-12-24T11:16:00Z","upstream":["CVE-2025-68366"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-68366"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.121.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-73081.json"}}],"schema_version":"1.7.5"}