{"id":"AZL-96525","summary":"CVE-2026-72073 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmmc: vub300: fix use-after-free on probe failure\n\nThe vub300 driver lifetime-manages its controller state using\nvub300-\u003ekref, with vub300_delete() freeing the mmc host when the last\nreference is dropped. The probe error path after the inactivity timer has\nbeen armed still bypasses that lifetime rule, however, and falls through\nto mmc_free_host() directly if mmc_add_host() fails.\n\nThe race window is between arming the inactivity timer and reaching the\nprobe error unwind after mmc_add_host() fails:\n\n        probe thread                     timer/workqueue\n        ------------                     ---------------\n        kref_init(&vub300-\u003ekref)         ref = 1\n        kref_get(&vub300-\u003ekref)          ref = 2, timer ref\n        add_timer(inactivity_timer)      fires after one second\n        |\n        |   race window\n        |\u003c----------------------------------------------------\u003e\n        |\n        mmc_add_host(mmc)\n                                         inactivity timer fires\n                                         vub300_queue_dead_work()\n                                           kref_get()          ref = 3\n                                           queue_work(deadwork)\n        mmc_add_host() fails\n        timer_delete_sync()\n        mmc_free_host(mmc)\n          frees vub300\n                                         deadwork runs\n                                           use-after-free\n\nThe inactivity timeout is one second, so this would require\nmmc_add_host() to both fail and take more than one second to do so. This\nis unlikely to happen in practice, but the error path is still wrong.\n\ntimer_delete_sync() only waits for the timer callback itself. It does\nnot flush deadwork that the callback may already have queued. As a\nresult, queued deadwork can still hold a kref while the probe error path\ndirectly frees the backing mmc host, including the vub300 storage.\n\nFix this by using the same lifetime mechanism as disconnect. Clear\nvub300-\u003einterface so that the timer callback and any queued deadwork\nreturn early and drop their references, then drop the initial probe\nreference and return without falling through to err_free_host.","modified":"2026-08-30T05:26:50Z","published":"2026-08-15T06:21:17Z","upstream":["CVE-2026-72073"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72073"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-96525.json"}}],"schema_version":"1.9.0"}