CVE-2026-98738
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Serialize SMP remote OOB data access
build_pairing_cmd() looks up remote OOB data and copies its contents without holding hdev->lock, which serializes the list's writers. After SMP finds an entry, a concurrent management Remove Remote OOB Data command can unlink and free it before SMP reads its present flag or copies its random and confirmation values. Removal can also invalidate an entry while the lookup is still traversing the list.
Taking hdev->lock in build_pairing_cmd() would recurse for callers that already hold it and invert the device-to-L2CAP lock order on the receive path.
Read full descriptionShow less
Add a per-device remote_oob_lock instead, held across the SMP lookup and copies and by the add, remove and clear helpers. Cover initialization and in-place updates as well, so SMP cannot read partially initialized or updated OOB values. Release the mutex on allocation failure, preserving the existing error return.
The new critical sections acquire no device, connection or channel locks. Writers retain their existing hdev->lock protection, which continues to serialize the other readers without changing their locking or behavior.
Technical details traces, logs and code from the original report
KASAN reported: BUG: KASAN: slab-use-after-free in build_pairing_cmd+0x948/0x9b0 Call Trace: build_pairing_cmd+0x948/0x9b0 smp_recv_cb+0x459f/0x8110 l2cap_recv_frame+0xf14/0x9190 l2cap_recv_acldata+0xa64/0xd40 hci_rx_work+0x4ca/0x730 Allocated by task 87: hci_add_remote_oob_data+0x11d/0x530 add_remote_oob_data+0x282/0x400 hci_sock_sendmsg+0x1033/0x1ea0 Freed by task 93: hci_remote_oob_data_clear+0x108/0x1c0 remove_remote_oob_data+0x198/0x220 hci_sock_sendmsg+0x1033/0x1ea0
CVSS
NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days
- 0.17 %
- Percentile among all scored CVEs
- 6
- Score date
- 10/20/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.
References
Show 4 references
Raw JSON (NVD)
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{
"id": "CVE-2026-98738",
"cveTags": [],
"metrics": {},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "02b05bd8b0a632e9a26795bced8f19ca6a5f7079",
"lessThan": "1e11412a1b9854a89d044576d616675b16141d87",
"versionType": "git"
},
{
"status": "affected",
"version": "02b05bd8b0a632e9a26795bced8f19ca6a5f7079",
"lessThan": "889c61e3d0f1091a958e4b2a24b20bab23d915c4",
"versionType": "git"
},
{
"status": "affected",
"version": "02b05bd8b0a632e9a26795bced8f19ca6a5f7079",
"lessThan": "df5162eeb10e69fe0c2349503882c4a09077f001",
"versionType": "git"
},
{
"status": "affected",
"version": "02b05bd8b0a632e9a26795bced8f19ca6a5f7079",
"lessThan": "81a2345f1984f0b36d3226571bc196316a01b648",
"versionType": "git"
}
],
"programFiles": [
"include/net/bluetooth/hci_core.h",
"net/bluetooth/hci_core.c",
"net/bluetooth/smp.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3.19"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "3.19",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.56",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.10",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/bluetooth/hci_core.h",
"net/bluetooth/hci_core.c",
"net/bluetooth/smp.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-10-18T16:17:27.477",
"references": [
{
"url": "https://git.kernel.org/stable/c/1e11412a1b9854a89d044576d616675b16141d87",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/81a2345f1984f0b36d3226571bc196316a01b648",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/889c61e3d0f1091a958e4b2a24b20bab23d915c4",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/df5162eeb10e69fe0c2349503882c4a09077f001",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: Serialize SMP remote OOB data access\n\nbuild_pairing_cmd() looks up remote OOB data and copies its contents\nwithout holding hdev->lock, which serializes the list's writers. After\nSMP finds an entry, a concurrent management Remove Remote OOB Data\ncommand can unlink and free it before SMP reads its present flag or\ncopies its random and confirmation values. Removal can also invalidate\nan entry while the lookup is still traversing the list.\n\nKASAN reported:\n\n BUG: KASAN: slab-use-after-free in build_pairing_cmd+0x948/0x9b0\n Call Trace:\n build_pairing_cmd+0x948/0x9b0\n smp_recv_cb+0x459f/0x8110\n l2cap_recv_frame+0xf14/0x9190\n l2cap_recv_acldata+0xa64/0xd40\n hci_rx_work+0x4ca/0x730\n\n Allocated by task 87:\n hci_add_remote_oob_data+0x11d/0x530\n add_remote_oob_data+0x282/0x400\n hci_sock_sendmsg+0x1033/0x1ea0\n\n Freed by task 93:\n hci_remote_oob_data_clear+0x108/0x1c0\n remove_remote_oob_data+0x198/0x220\n hci_sock_sendmsg+0x1033/0x1ea0\n\nTaking hdev->lock in build_pairing_cmd() would recurse for callers that\nalready hold it and invert the device-to-L2CAP lock order on the receive\npath. Add a per-device remote_oob_lock instead, held across the SMP\nlookup and copies and by the add, remove and clear helpers. Cover\ninitialization and in-place updates as well, so SMP cannot read partially\ninitialized or updated OOB values. Release the mutex on allocation\nfailure, preserving the existing error return.\n\nThe new critical sections acquire no device, connection or channel locks.\nWriters retain their existing hdev->lock protection, which continues to\nserialize the other readers without changing their locking or behavior."
}
],
"lastModified": "2026-10-19T10:19:37.950",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}