CVE-2026-99011 (GCVE-0-2026-99011)
Vulnerability from cvelistv5
Published
2026-10-23 12:20
Modified
2026-10-24 14:09
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/sco.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "b108ea7ebba147465f4158d8133f0e8f013762ed",
"status": "affected",
"version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
"versionType": "git"
},
{
"lessThan": "8a98d58f6cfe70d51138cd9ce894e72671d95f8a",
"status": "affected",
"version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
"versionType": "git"
},
{
"lessThan": "816fb1590a4c8cf8d05cd076057616be02e276f0",
"status": "affected",
"version": "e6720779ae612a14ac4ba7fe4fd5b27d900d932c",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/bluetooth/sco.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": "6.18.57",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.57",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.11",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3",
"versionStartIncluding": "6.13",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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-\u003esco_data back-pointer to a\nstrong reference under hdev-\u003elock:\n\n hci_dev_lock(hdev);\n hcon = hci_conn_hash_lookup_handle(hdev, handle);\n ...\n conn = sco_conn_hold_unless_zero(hcon-\u003esco_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-\u003ehcon-\u003esco_data = NULL;\n\nwith no hdev-\u003elock held, so the RX path could read hcon-\u003esco_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-\u003esco_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-\u003elock (its\ncallers, sco_connect_cfm() and sco_disconn_cfm(), hold it). The reader in\nsco_recv_scodata() also takes hdev-\u003elock, 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\u0027s only reference; that initial reference is the one owned\nby hcon-\u003esco_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."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:A - An in-range peer\u0027s Bluetooth SCO/eSCO data enters as HCI_SCODATA_PKT through hci_recv_frame() \u2192 hci_rx_work() \u2192 hci_scodata_packet() \u2192 the patched sco_recv_scodata(). The radio-range transport makes the vector Adjacent.\nAC:H - Peer-induced Disconnection Complete runs on the same ordered HCI workqueue and calls sco_conn_del() under hdev-\u003elock, so it cannot create this race. Exploitation must instead coincide with local close()/shutdown() freeing the sco_conn outside that lock, timing the peer cannot control.\nPR:N - hci_scodata_packet() and sco_recv_scodata() impose no peer credential or capability check once a SCO/eSCO handle exists. For inbound setup, sco_connect_ind() checks only for a listening SCO socket, not authentication.\nUI:R - The last reference must be dropped through victim-side sco_sock_release() or sco_sock_shutdown() while peer data is received. Because peer-driven sco_disconn_cfm() is serialized against receive processing, a separate victim socket teardown is required.\nS:U - The stale hcon-\u003esco_data pointer corrupts a freed sco_conn inside the host Bluetooth kernel stack; it does not cross a VM, IOMMU, or other security-authority boundary.\nC:H - After sco_conn_hold_unless_zero() revives reclaimed storage, sco_recv_frame() reads the reused conn-\u003esk pointer and socket state. Heap grooming can therefore turn the sco_conn UAF into kernel-memory disclosure.\nI:H - kref_get_unless_zero() performs a four-byte atomic increment in the freed sco_conn, followed on success by spinlock and kref operations on reclaimed storage. Reuse can convert these writes into kernel heap corruption and control-flow hijacking.\nA:H - The demonstrated stale reference causes a KASAN slab-use-after-free write in sco_conn_hold_unless_zero() from hci_rx_work; such corruption can produce an oops or kernel panic."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-24T14:09:59.382Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/b108ea7ebba147465f4158d8133f0e8f013762ed"
},
{
"url": "https://git.kernel.org/stable/c/8a98d58f6cfe70d51138cd9ce894e72671d95f8a"
},
{
"url": "https://git.kernel.org/stable/c/816fb1590a4c8cf8d05cd076057616be02e276f0"
}
],
"title": "Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-99011",
"datePublished": "2026-10-23T12:20:36.460Z",
"dateReserved": "2026-09-25T10:25:14.385Z",
"dateUpdated": "2026-10-24T14:09:59.382Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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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.
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