{"id":"CVE-2026-72073","title":"mmc: vub300: fix use-after-free on probe failure","summary":"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->kref, with vub300_delete() freeing the mmc host …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < face65f80c6946c631ca3490b4ebd2c016a4fd2c","Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < 6c66653dac9b25272d5fd4ed42a34aa5249e16df","Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < 5b82af744e06cd741938c3da54fdbe564a7e52d9","Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < 618cf6b139503ec18ef93ffd663396aaf99b763a","Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < a3b5f242997a3be7404112fd48784881560aea57","Linux 41ed46bdbd2878cd6567abe0974a445f8b1b8ec8","Linux 25f05d762ca5e1c685002a53dd44f68e78ca3feb","Linux a46e681151bbdacdf6b89ee8c4e5bad0555142bb","Linux 3b29f8769d32016b2d89183db4d80c7a71b7e35e","Linux 3049a3b927a40d89d4582ff1033cd7953be773c7","Linux afc898019e7bf18c5eb7a0ac19852fcb1b341b3c","Linux c9e85979b59cb86f0a15defa8199d740e2b36b90","Linux 2044b2ea77945f372ef161d1bbf814e471767ff2","Linux >= 4.9.337 < 4.10","Linux >= 4.14.303 < 4.15","Linux >= 4.19.270 < 4.20","Linux >= 5.4.229 < 5.5","Linux >= 5.10.163 < 5.11","Linux >= 5.15.86 < 5.16","Linux >= 6.0.16 < 6.1","Linux >= 6.1.2 < 6.2","Linux 6.2"],"published":"2026-08-15","updated":"2026-10-21","sourceUpdated":"2026-10-21T12:44:20.898Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72073","references":[{"url":"https://git.kernel.org/stable/c/face65f80c6946c631ca3490b4ebd2c016a4fd2c"},{"url":"https://git.kernel.org/stable/c/6c66653dac9b25272d5fd4ed42a34aa5249e16df"},{"url":"https://git.kernel.org/stable/c/5b82af744e06cd741938c3da54fdbe564a7e52d9"},{"url":"https://git.kernel.org/stable/c/618cf6b139503ec18ef93ffd663396aaf99b763a"},{"url":"https://git.kernel.org/stable/c/a3b5f242997a3be7404112fd48784881560aea57"}],"tags":["cve.org"],"epss":0.00219,"epssPercentile":0.11679,"ingestedAt":"2026-10-21T12:48:53.595Z","slug":"CVE-2026-72073","body":"## Overview\n\nIn 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->kref, 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->kref)         ref = 1\n        kref_get(&vub300->kref)          ref = 2, timer ref\n        add_timer(inactivity_timer)      fires after one second\n        |\n        |   race window\n        |<---------------------------------------------------->\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->interface 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.\n\n## Affected\n\n- `Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < face65f80c6946c631ca3490b4ebd2c016a4fd2c`\n- `Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < 6c66653dac9b25272d5fd4ed42a34aa5249e16df`\n- `Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < 5b82af744e06cd741938c3da54fdbe564a7e52d9`\n- `Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < 618cf6b139503ec18ef93ffd663396aaf99b763a`\n- `Linux >= 0613ad2401f88bdeae5594c30afe318e93b14676 < a3b5f242997a3be7404112fd48784881560aea57`\n- `Linux 41ed46bdbd2878cd6567abe0974a445f8b1b8ec8`\n- `Linux 25f05d762ca5e1c685002a53dd44f68e78ca3feb`\n- `Linux a46e681151bbdacdf6b89ee8c4e5bad0555142bb`\n- `Linux 3b29f8769d32016b2d89183db4d80c7a71b7e35e`\n- `Linux 3049a3b927a40d89d4582ff1033cd7953be773c7`\n- `Linux afc898019e7bf18c5eb7a0ac19852fcb1b341b3c`\n- `Linux c9e85979b59cb86f0a15defa8199d740e2b36b90`\n- `Linux 2044b2ea77945f372ef161d1bbf814e471767ff2`\n- `Linux >= 4.9.337 < 4.10`\n- `Linux >= 4.14.303 < 4.15`\n- `Linux >= 4.19.270 < 4.20`\n- `Linux >= 5.4.229 < 5.5`\n- `Linux >= 5.10.163 < 5.11`\n- `Linux >= 5.15.86 < 5.16`\n- `Linux >= 6.0.16 < 6.1`\n- `Linux >= 6.1.2 < 6.2`\n- `Linux 6.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}