CVE-2026-90251
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: MSFT: validate evt_prefix_len against the response length
read_supported_features() only checks that the response covers the fixed part of struct msft_rp_read_supported_features, which is 11 bytes:
evt_prefix[] is a flexible array member and rp->evt_prefix_len is an unvalidated u8 taken straight out of that response, so
copies up to 255 bytes from a reply that may have carried none of them. What is copied is data the controller never sent, and it is then used to match incoming vendor events in msft_vendor_evt().
This is not an out-of-bounds access. An skb data allocation always has at least SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) bytes past the payload, which is more than the 255 byte maximum, so the read stays inside the allocation and KASAN does not report it. It is still a read of bytes the host was never given, with the length fully controlled by the controller.
Leer descripción completaMostrar menos
Reject a response that is too short for the prefix it declares.
Verified with an emulated controller over /dev/vhci on a KASAN kernel, with vhci made to advertise an MSFT opcode the way btintel, btqca, btmtk and btrtl do unconditionally. A reply of exactly 11 bytes declaring evt_prefix_len = 255 reaches kmemdup and copies 255 bytes ("skb->len=11 evt_prefix_len=255", with the copied buffer dumped); since the reply ends at the fixed part, all 255 come from past the end of the response. No KASAN report is produced, as expected from the allocation slack described above. With this patch the response is rejected with "MSFT event prefix length mismatch" and msft->evt_prefix is left unset.
Detalles técnicos trazas, registros y código del informe original
if (skb->len < sizeof(*rp)) {
bt_dev_err(hdev, "MSFT supported features length mismatch");
goto failed;
}
msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
GFP_KERNEL);CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.21%
- Percentil entre todas las CVEs puntuadas: 10
- Fecha de la puntuación: 5/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
- https://git.kernel.org/stable/c/0079e1a944634ab2dc1c7cdec1144486d096407e
- https://git.kernel.org/stable/c/21f539c59ed330b671d75fd119c5f659ff92fbd1
- https://git.kernel.org/stable/c/52b1b3b4d403cbda1b70ce2385e1a71f166a87ba
- https://git.kernel.org/stable/c/620c2631cff490d14d0b9d56f185cc745806d6d7
- https://git.kernel.org/stable/c/63562cfaea8a650fdb31ee8de21c32e3600be642
- https://git.kernel.org/stable/c/7c2658023d839b651368a5b8b781bf9a817647cb
- https://git.kernel.org/stable/c/dce783a10e70f013410f5b583a29fc3286899629
- https://git.kernel.org/stable/c/e804d54a5a99d99250490e68093eff7190472e6f
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-90251",
"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": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "dce783a10e70f013410f5b583a29fc3286899629",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "21f539c59ed330b671d75fd119c5f659ff92fbd1",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "52b1b3b4d403cbda1b70ce2385e1a71f166a87ba",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "e804d54a5a99d99250490e68093eff7190472e6f",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "620c2631cff490d14d0b9d56f185cc745806d6d7",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "7c2658023d839b651368a5b8b781bf9a817647cb",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "63562cfaea8a650fdb31ee8de21c32e3600be642",
"versionType": "git"
},
{
"status": "affected",
"version": "145373cb1b1fcdba2059e945d0aa2613af2e84d1",
"lessThan": "0079e1a944634ab2dc1c7cdec1144486d096407e",
"versionType": "git"
}
],
"programFiles": [
"net/bluetooth/msft.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bluetooth/msft.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-09-17T17:17:21.350",
"references": [
{
"url": "https://git.kernel.org/stable/c/0079e1a944634ab2dc1c7cdec1144486d096407e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/21f539c59ed330b671d75fd119c5f659ff92fbd1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/52b1b3b4d403cbda1b70ce2385e1a71f166a87ba",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/620c2631cff490d14d0b9d56f185cc745806d6d7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/63562cfaea8a650fdb31ee8de21c32e3600be642",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7c2658023d839b651368a5b8b781bf9a817647cb",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/dce783a10e70f013410f5b583a29fc3286899629",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e804d54a5a99d99250490e68093eff7190472e6f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: MSFT: validate evt_prefix_len against the response length\n\nread_supported_features() only checks that the response covers the fixed\npart of struct msft_rp_read_supported_features, which is 11 bytes:\n\n\tif (skb->len < sizeof(*rp)) {\n\t\tbt_dev_err(hdev, \"MSFT supported features length mismatch\");\n\t\tgoto failed;\n\t}\n\nevt_prefix[] is a flexible array member and rp->evt_prefix_len is an\nunvalidated u8 taken straight out of that response, so\n\n\tmsft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,\n\t\t\t\t GFP_KERNEL);\n\ncopies up to 255 bytes from a reply that may have carried none of them.\nWhat is copied is data the controller never sent, and it is then used to\nmatch incoming vendor events in msft_vendor_evt().\n\nThis is not an out-of-bounds access. An skb data allocation always has\nat least SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) bytes past the\npayload, which is more than the 255 byte maximum, so the read stays\ninside the allocation and KASAN does not report it. It is still a read\nof bytes the host was never given, with the length fully controlled by\nthe controller.\n\nReject a response that is too short for the prefix it declares.\n\nVerified with an emulated controller over /dev/vhci on a KASAN kernel,\nwith vhci made to advertise an MSFT opcode the way btintel, btqca, btmtk\nand btrtl do unconditionally. A reply of exactly 11 bytes declaring\nevt_prefix_len = 255 reaches kmemdup and copies 255 bytes\n(\"skb->len=11 evt_prefix_len=255\", with the copied buffer dumped); since\nthe reply ends at the fixed part, all 255 come from past the end of the\nresponse. No KASAN report is produced, as expected from the allocation\nslack described above. With this patch the response is rejected with\n\"MSFT event prefix length mismatch\" and msft->evt_prefix is left unset."
}
],
"lastModified": "2026-09-17T17:17:21.350",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}