CVE-2026-31771 (GCVE-0-2026-31771)
Vulnerability from cvelistv5 – Published: 2026-05-01 14:14 – Updated: 2026-05-11 22:15
VLAI?
Title
Bluetooth: hci_event: move wake reason storage into validated event handlers
Summary
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: move wake reason storage into validated event handlers
hci_store_wake_reason() is called from hci_event_packet() immediately
after stripping the HCI event header but before hci_event_func()
enforces the per-event minimum payload length from hci_ev_table.
This means a short HCI event frame can reach bacpy() before any bounds
check runs.
Rather than duplicating skb parsing and per-event length checks inside
hci_store_wake_reason(), move wake-address storage into the individual
event handlers after their existing event-length validation has
succeeded. Convert hci_store_wake_reason() into a small helper that only
stores an already-validated bdaddr while the caller holds hci_dev_lock().
Use the same helper after hci_event_func() with a NULL address to
preserve the existing unexpected-wake fallback semantics when no
validated event handler records a wake address.
Annotate the helper with __must_hold(&hdev->lock) and add
lockdep_assert_held(&hdev->lock) so future call paths keep the lock
contract explicit.
Call the helper from hci_conn_request_evt(), hci_conn_complete_evt(),
hci_sync_conn_complete_evt(), le_conn_complete_evt(),
hci_le_adv_report_evt(), hci_le_ext_adv_report_evt(),
hci_le_direct_adv_report_evt(), hci_le_pa_sync_established_evt(), and
hci_le_past_received_evt().
Severity ?
8.1 (High)
Assigner
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/bluetooth/hci_event.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
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"status": "affected",
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"versionType": "git"
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{
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"status": "affected",
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]
},
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"programFiles": [
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],
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"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.10"
},
{
"lessThan": "5.10",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.12",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.12",
"versionStartIncluding": "5.10",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0",
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"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_event: move wake reason storage into validated event handlers\n\nhci_store_wake_reason() is called from hci_event_packet() immediately\nafter stripping the HCI event header but before hci_event_func()\nenforces the per-event minimum payload length from hci_ev_table.\nThis means a short HCI event frame can reach bacpy() before any bounds\ncheck runs.\n\nRather than duplicating skb parsing and per-event length checks inside\nhci_store_wake_reason(), move wake-address storage into the individual\nevent handlers after their existing event-length validation has\nsucceeded. Convert hci_store_wake_reason() into a small helper that only\nstores an already-validated bdaddr while the caller holds hci_dev_lock().\nUse the same helper after hci_event_func() with a NULL address to\npreserve the existing unexpected-wake fallback semantics when no\nvalidated event handler records a wake address.\n\nAnnotate the helper with __must_hold(\u0026hdev-\u003elock) and add\nlockdep_assert_held(\u0026hdev-\u003elock) so future call paths keep the lock\ncontract explicit.\n\nCall the helper from hci_conn_request_evt(), hci_conn_complete_evt(),\nhci_sync_conn_complete_evt(), le_conn_complete_evt(),\nhci_le_adv_report_evt(), hci_le_ext_adv_report_evt(),\nhci_le_direct_adv_report_evt(), hci_le_pa_sync_established_evt(), and\nhci_le_past_received_evt()."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.1,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
"version": "3.1"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-05-11T22:15:29.721Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
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"references": [
{
"url": "https://git.kernel.org/stable/c/86c8d07a64d553c41e213b52650020010f9ef23e"
},
{
"url": "https://git.kernel.org/stable/c/2b2bf47cd75518c36fa2d41380e4a40641cc89cd"
}
],
"title": "Bluetooth: hci_event: move wake reason storage into validated event handlers",
"x_generator": {
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-31771",
"datePublished": "2026-05-01T14:14:59.918Z",
"dateReserved": "2026-03-09T15:48:24.140Z",
"dateUpdated": "2026-05-11T22:15:29.721Z",
"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 observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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