FKIE_CVE-2026-72073
Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
mmc: vub300: fix use-after-free on probe failure
The vub300 driver lifetime-manages its controller state using
vub300->kref, with vub300_delete() freeing the mmc host when the last
reference is dropped. The probe error path after the inactivity timer has
been armed still bypasses that lifetime rule, however, and falls through
to mmc_free_host() directly if mmc_add_host() fails.
The race window is between arming the inactivity timer and reaching the
probe error unwind after mmc_add_host() fails:
probe thread timer/workqueue
------------ ---------------
kref_init(&vub300->kref) ref = 1
kref_get(&vub300->kref) ref = 2, timer ref
add_timer(inactivity_timer) fires after one second
|
| race window
|<---------------------------------------------------->
|
mmc_add_host(mmc)
inactivity timer fires
vub300_queue_dead_work()
kref_get() ref = 3
queue_work(deadwork)
mmc_add_host() fails
timer_delete_sync()
mmc_free_host(mmc)
frees vub300
deadwork runs
use-after-free
The inactivity timeout is one second, so this would require
mmc_add_host() to both fail and take more than one second to do so. This
is unlikely to happen in practice, but the error path is still wrong.
timer_delete_sync() only waits for the timer callback itself. It does
not flush deadwork that the callback may already have queued. As a
result, queued deadwork can still hold a kref while the probe error path
directly frees the backing mmc host, including the vub300 storage.
Fix this by using the same lifetime mechanism as disconnect. Clear
vub300->interface so that the timer callback and any queued deadwork
return early and drop their references, then drop the initial probe
reference and return without falling through to err_free_host.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/mmc/host/vub300.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "5b82af744e06cd741938c3da54fdbe564a7e52d9",
"status": "affected",
"version": "0613ad2401f88bdeae5594c30afe318e93b14676",
"versionType": "git"
},
{
"lessThan": "618cf6b139503ec18ef93ffd663396aaf99b763a",
"status": "affected",
"version": "0613ad2401f88bdeae5594c30afe318e93b14676",
"versionType": "git"
},
{
"lessThan": "a3b5f242997a3be7404112fd48784881560aea57",
"status": "affected",
"version": "0613ad2401f88bdeae5594c30afe318e93b14676",
"versionType": "git"
},
{
"status": "affected",
"version": "41ed46bdbd2878cd6567abe0974a445f8b1b8ec8",
"versionType": "git"
},
{
"status": "affected",
"version": "25f05d762ca5e1c685002a53dd44f68e78ca3feb",
"versionType": "git"
},
{
"status": "affected",
"version": "a46e681151bbdacdf6b89ee8c4e5bad0555142bb",
"versionType": "git"
},
{
"status": "affected",
"version": "3b29f8769d32016b2d89183db4d80c7a71b7e35e",
"versionType": "git"
},
{
"status": "affected",
"version": "3049a3b927a40d89d4582ff1033cd7953be773c7",
"versionType": "git"
},
{
"status": "affected",
"version": "afc898019e7bf18c5eb7a0ac19852fcb1b341b3c",
"versionType": "git"
},
{
"status": "affected",
"version": "c9e85979b59cb86f0a15defa8199d740e2b36b90",
"versionType": "git"
},
{
"status": "affected",
"version": "2044b2ea77945f372ef161d1bbf814e471767ff2",
"versionType": "git"
},
{
"lessThan": "4.10",
"status": "affected",
"version": "4.9.337",
"versionType": "semver"
},
{
"lessThan": "4.15",
"status": "affected",
"version": "4.14.303",
"versionType": "semver"
},
{
"lessThan": "4.20",
"status": "affected",
"version": "4.19.270",
"versionType": "semver"
},
{
"lessThan": "5.5",
"status": "affected",
"version": "5.4.229",
"versionType": "semver"
},
{
"lessThan": "5.11",
"status": "affected",
"version": "5.10.163",
"versionType": "semver"
},
{
"lessThan": "5.16",
"status": "affected",
"version": "5.15.86",
"versionType": "semver"
},
{
"lessThan": "6.1",
"status": "affected",
"version": "6.0.16",
"versionType": "semver"
},
{
"lessThan": "6.2",
"status": "affected",
"version": "6.1.2",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/mmc/host/vub300.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.2"
},
{
"lessThan": "6.2",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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(\u0026vub300-\u003ekref) ref = 1\n kref_get(\u0026vub300-\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."
}
],
"id": "CVE-2026-72073",
"lastModified": "2026-08-17T06:18:05.977",
"metrics": {},
"published": "2026-08-15T06:21:17.123",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/5b82af744e06cd741938c3da54fdbe564a7e52d9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/618cf6b139503ec18ef93ffd663396aaf99b763a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a3b5f242997a3be7404112fd48784881560aea57"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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