CVE-2026-74534 (GCVE-0-2026-74534)
Vulnerability from cvelistv5
Published
2026-08-15 12:27
Modified
2026-08-17 05:48
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: fix refcounting of iso_conn
iso_conn_del() and iso_chan_del() have a race that results to double-put
of iso_conn:
[Task hdev->workqueue] [Task 2]
iso_conn_del iso_chan_del
iso_conn_hold_unless_zero iso_conn_lock
iso_conn_lock conn->sk = NULL
iso_conn_unlock
sk = iso_sock_hold(conn) <---------´
if (!sk) iso_conn_put iso_conn_put
iso_conn_put /* UAF */
The extra put for !sk in iso_conn_del() is currently required since
failing iso_chan_add() may leave iso_conn not associated with any sk.
Fix by having iso_pi(sk)->conn own refcount when non-NULL, so
iso_conn_del does not need to put it. Adjust the iso_conn_add()
refcounting so that conn is put if it does not get associated with an
sk.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: dc26097bdb864a0d5955b9a25e43376ffc1af99b Version: dc26097bdb864a0d5955b9a25e43376ffc1af99b Version: dc26097bdb864a0d5955b9a25e43376ffc1af99b Version: f53e7489273dc2bb307bf50f319b3762d45534f0 Version: a58d0f5dac322e16cc75334d000666512341bde5 Version: 6.11.11 ≤ Version: 6.12.2 ≤ |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/iso.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "3b921533e8aa95b77aadcf31737595578e735f3c",
"status": "affected",
"version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
"versionType": "git"
},
{
"lessThan": "8208b4939afb0a1977fffe902c3ca42fe0f3baaa",
"status": "affected",
"version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
"versionType": "git"
},
{
"lessThan": "fdfde532ab1caa165fcd8985001157ac8b4db365",
"status": "affected",
"version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
"versionType": "git"
},
{
"status": "affected",
"version": "f53e7489273dc2bb307bf50f319b3762d45534f0",
"versionType": "git"
},
{
"status": "affected",
"version": "a58d0f5dac322e16cc75334d000666512341bde5",
"versionType": "git"
},
{
"lessThan": "6.12",
"status": "affected",
"version": "6.11.11",
"versionType": "semver"
},
{
"lessThan": "6.13",
"status": "affected",
"version": "6.12.2",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bluetooth/iso.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.13"
},
{
"lessThan": "6.13",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.44",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.8",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.11.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "6.12.2",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: fix refcounting of iso_conn\n\niso_conn_del() and iso_chan_del() have a race that results to double-put\nof iso_conn:\n\n [Task hdev-\u003eworkqueue] [Task 2]\n iso_conn_del iso_chan_del\n iso_conn_hold_unless_zero iso_conn_lock\n iso_conn_lock conn-\u003esk = NULL\n iso_conn_unlock\n sk = iso_sock_hold(conn) \u003c---------\u00b4\n if (!sk) iso_conn_put iso_conn_put\n iso_conn_put /* UAF */\n\nThe extra put for !sk in iso_conn_del() is currently required since\nfailing iso_chan_add() may leave iso_conn not associated with any sk.\n\nFix by having iso_pi(sk)-\u003econn own refcount when non-NULL, so\niso_conn_del does not need to put it. Adjust the iso_conn_add()\nrefcounting so that conn is put if it does not get associated with an\nsk."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:A - The bug is in Bluetooth ISO connection teardown; a remote LE Audio/CIS/BIS peer in range can trigger iso_conn_del via HCI disconnect events (iso_disconn_cfm) that race with concurrent socket teardown.\nAC:L - The double kref_put race is between iso_conn_del and iso_chan_del; an adjacent attacker controls disconnect timing and can repeatedly connect/disconnect to race automatic kernel and Bluetooth daemon socket cleanup.\nPR:N - No local UNIX privileges are required; a malicious or compromised adjacent Bluetooth ISO peer with an established connection can initiate the disconnect leg without root, capabilities, or user-namespace admin rights.\nUI:N - No explicit victim action is needed beyond an active ISO session; remote disconnect triggers automatic HCI teardown and stack socket close that can race iso_chan_del without the user manually closing applications.\nS:U - The vulnerability corrupts kernel heap lifetime of iso_conn objects within the Bluetooth subsystem and does not cross VM, hypervisor, or IOMMU security boundaries.\nC:H - Premature kfree of iso_conn from the refcount race is a use-after-free that can expose kernel heap contents and be leveraged for arbitrary kernel memory disclosure.\nI:H - UAF on iso_conn enables heap grooming and corrupted pointer dereferences that can be leveraged for arbitrary kernel memory writes or privilege-escalating code execution.\nA:H - The double iso_conn_put can free iso_conn while still referenced, causing kernel oops/panic or reliably exploitable instability during ISO connection teardown."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:48:23.337Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/3b921533e8aa95b77aadcf31737595578e735f3c"
},
{
"url": "https://git.kernel.org/stable/c/8208b4939afb0a1977fffe902c3ca42fe0f3baaa"
},
{
"url": "https://git.kernel.org/stable/c/fdfde532ab1caa165fcd8985001157ac8b4db365"
}
],
"title": "Bluetooth: ISO: fix refcounting of iso_conn",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74534",
"datePublished": "2026-08-15T12:27:47.831Z",
"dateReserved": "2026-08-15T05:44:03.913Z",
"dateUpdated": "2026-08-17T05:48:23.337Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…