CVE-2026-89569
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: RFCOMM: serialize security confirmation handling rfcomm_security_cfm() looks up a session on session_list and then walks its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown uses rfcomm_mutex, krfcommd can close and free the same session and DLCs concurrently: hci_rx_work krfcommd ----------- --------- rfcomm_session_get() rfcomm_lock() rfcomm_session_close() rfcomm_dlc_unlink() rfcomm_session_del() kfree(s) rfcomm_unlock() walk s->dlcs The callback can then read a freed session list head and touch freed DLCs while updating their flags or timers. Serialize the session lookup and DLC traversal in rfcomm_security_cfm() with rfcomm_mutex. This matches the existing RFCOMM session lifetime rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink() from tearing the objects down while the callback is using them. KASAN reported: BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440 Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89 Workqueue: hci0 hci_rx_work Call Trace: rfcomm_security_cfm+0x41c/0x440 hci_encrypt_cfm+0x139/0x590 hci_encrypt_change_evt+0x37b/0xc40 hci_event_packet+0x71b/0xb20 hci_rx_work+0x293/0x730 Allocated by task 69: rfcomm_session_add+0x9e/0x2f0 rfcomm_run+0x44b/0x41e0 Freed by task 69: kfree+0x131/0x3c0 rfcomm_session_del+0x188/0x220 rfcomm_run+0x1985/0x41e0
View original CVE JSON
{
"id": "CVE-2026-89569",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-11T20:19:40.920",
"lastModified": "2026-10-19T09:17:52.730",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: RFCOMM: serialize security confirmation handling\n\nrfcomm_security_cfm() looks up a session on session_list and then walks\nits DLC list without holding rfcomm_mutex. Since RFCOMM session teardown\nuses rfcomm_mutex, krfcommd can close and free the same session and DLCs\nconcurrently:\n\n hci_rx_work krfcommd\n ----------- ---------\n rfcomm_session_get()\n rfcomm_lock()\n rfcomm_session_close()\n rfcomm_dlc_unlink()\n rfcomm_session_del()\n kfree(s)\n rfcomm_unlock()\n walk s->dlcs\n\nThe callback can then read a freed session list head and touch freed DLCs\nwhile updating their flags or timers.\n\nSerialize the session lookup and DLC traversal in rfcomm_security_cfm()\nwith rfcomm_mutex. This matches the existing RFCOMM session lifetime\nrules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()\nfrom tearing the objects down while the callback is using them.\n\nKASAN reported:\n\n BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440\n Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89\n Workqueue: hci0 hci_rx_work\n Call Trace:\n rfcomm_security_cfm+0x41c/0x440\n hci_encrypt_cfm+0x139/0x590\n hci_encrypt_change_evt+0x37b/0xc40\n hci_event_packet+0x71b/0xb20\n hci_rx_work+0x293/0x730\n Allocated by task 69:\n rfcomm_session_add+0x9e/0x2f0\n rfcomm_run+0x44b/0x41e0\n Freed by task 69:\n kfree+0x131/0x3c0\n rfcomm_session_del+0x188/0x220\n rfcomm_run+0x1985/0x41e0"
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/bluetooth/rfcomm/core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"lessThan": "62ce8b33eb238cf18c15207332fbdc26d858f592",
"versionType": "git",
"status": "affected"
},
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"versionType": "git",
"status": "affected"
},
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"lessThan": "7ded3264106418c6456ccceaafd9fda596ce12c3",
"versionType": "git",
"status": "affected"
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{
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{
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"lessThan": "fbf7961964a6e93360179f64712320ae9a1e9577",
"versionType": "git",
"status": "affected"
},
{
"version": "08c30aca9e698faddebd34f81e1196295f9dc063",
"lessThan": "759c185d0bbdb131357408f50b8735e04ed3caff",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/bluetooth/rfcomm/core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.10",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.270",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.221",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.188",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.157",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.109",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.50",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.4",
"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:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "ADJACENT_NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T19:24:18.874687Z",
"id": "CVE-2026-89569",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
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"url": "https://git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940",
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}