CVE-2026-99011
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata() sco_recv_scodata() upgrades the weak hcon->sco_data back-pointer to a strong reference under hdev->lock: hci_dev_lock(hdev); hcon = hci_conn_hash_lookup_handle(hdev, handle); ... conn = sco_conn_hold_unless_zero(hcon->sco_data); hci_dev_unlock(hdev); but the pointer is cleared from the other side without that lock. When the last sco_conn reference is dropped, sco_conn_free() ran conn->hcon->sco_data = NULL; with no hdev->lock held, so the RX path could read hcon->sco_data and call kref_get_unless_zero() on an sco_conn that was concurrently freed: BUG: KASAN: slab-use-after-free in sco_conn_hold_unless_zero+0xbe/0x160 Write of size 4 by task kworker/u17:0 Workqueue: hci0 hci_rx_work Call Trace: sco_conn_hold_unless_zero+0xbe/0x160 sco_recv_scodata+0x13f/0x490 hci_rx_work+0x3af/0x730 kref_get_unless_zero() only guards against a zero refcount, not against the backing memory already being freed. Give hcon->sco_data an actual reference on the sco_conn it points to, so the object cannot be freed while the pointer is still installed, and only clear and drop it from sco_conn_del(), which runs under hdev->lock (its callers, sco_connect_cfm() and sco_disconn_cfm(), hold it). The reader in sco_recv_scodata() also takes hdev->lock, so the store and the read are now serialised: the RX path either observes NULL or a reference that is guaranteed to stay valid until it drops its own. sco_conn_add() no longer hands its kref_init() reference to the caller as the connection's only reference; that initial reference is the one owned by hcon->sco_data, and callers get their own via sco_conn_hold(). Because the sco_conn can now outlive the socket (the association keeps it alive until the link goes down), the hci_conn can no longer be dropped from sco_conn_free() without regressing socket close: closing a connected SCO socket must still tear the link down. Move hci_conn ownership to the socket instead: __sco_chan_add() takes an hci_conn reference and it is released from sco_chan_del() and sco_sock_destruct(), exactly once. The sco_conn no longer owns an hci_conn reference, so sco_conn_add() stops consuming one and sco_connect() drops the hci_connect_sco() reference on every path; sco_connect_cfm() no longer needs its hci_conn_hold() dance.
View original CVE JSON
{
"id": "CVE-2026-99011",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-10-23T13:17:23.740",
"lastModified": "2026-10-24T14:16:52.047",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata()\n\nsco_recv_scodata() upgrades the weak hcon->sco_data back-pointer to a\nstrong reference under hdev->lock:\n\n hci_dev_lock(hdev);\n hcon = hci_conn_hash_lookup_handle(hdev, handle);\n ...\n conn = sco_conn_hold_unless_zero(hcon->sco_data);\n hci_dev_unlock(hdev);\n\nbut the pointer is cleared from the other side without that lock. When\nthe last sco_conn reference is dropped, sco_conn_free() ran\n\n conn->hcon->sco_data = NULL;\n\nwith no hdev->lock held, so the RX path could read hcon->sco_data and\ncall kref_get_unless_zero() on an sco_conn that was concurrently freed:\n\n BUG: KASAN: slab-use-after-free in sco_conn_hold_unless_zero+0xbe/0x160\n Write of size 4 by task kworker/u17:0\n Workqueue: hci0 hci_rx_work\n Call Trace:\n sco_conn_hold_unless_zero+0xbe/0x160\n sco_recv_scodata+0x13f/0x490\n hci_rx_work+0x3af/0x730\n\nkref_get_unless_zero() only guards against a zero refcount, not against\nthe backing memory already being freed.\n\nGive hcon->sco_data an actual reference on the sco_conn it points to, so\nthe object cannot be freed while the pointer is still installed, and only\nclear and drop it from sco_conn_del(), which runs under hdev->lock (its\ncallers, sco_connect_cfm() and sco_disconn_cfm(), hold it). The reader in\nsco_recv_scodata() also takes hdev->lock, so the store and the read are\nnow serialised: the RX path either observes NULL or a reference that is\nguaranteed to stay valid until it drops its own.\n\nsco_conn_add() no longer hands its kref_init() reference to the caller as\nthe connection's only reference; that initial reference is the one owned\nby hcon->sco_data, and callers get their own via sco_conn_hold().\n\nBecause the sco_conn can now outlive the socket (the association keeps it\nalive until the link goes down), the hci_conn can no longer be dropped\nfrom sco_conn_free() without regressing socket close: closing a connected\nSCO socket must still tear the link down. Move hci_conn ownership to the\nsocket instead: __sco_chan_add() takes an hci_conn reference and it is\nreleased from sco_chan_del() and sco_sock_destruct(), exactly once. The\nsco_conn no longer owns an hci_conn reference, so sco_conn_add() stops\nconsuming one and sco_connect() drops the hci_connect_sco() reference on\nevery path; sco_connect_cfm() no longer needs its hci_conn_hold() dance."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/bluetooth/sco.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
"lessThan": "b108ea7ebba147465f4158d8133f0e8f013762ed",
"versionType": "git",
"status": "affected"
},
{
"version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
"lessThan": "8a98d58f6cfe70d51138cd9ce894e72671d95f8a",
"versionType": "git",
"status": "affected"
},
{
"version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
"lessThan": "816fb1590a4c8cf8d05cd076057616be02e276f0",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/bluetooth/sco.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.13",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.13",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.57",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.11",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"attackVector": "ADJACENT_NETWORK",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "REQUIRED",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.2,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/816fb1590a4c8cf8d05cd076057616be02e276f0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8a98d58f6cfe70d51138cd9ce894e72671d95f8a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b108ea7ebba147465f4158d8133f0e8f013762ed",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}