Bluetooth: MSFT: validate evt_prefix_len against the response length
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: if (skb->len < sizeof(*rp)) { bt_dev_err(hdev, "MSFT supported features length mismatch"); goto failed; } evt_prefix[] is a flexible array member and rp->evt_prefix_len is an unvalidated u8 taken straight out of that response, so msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len, GFP_KERNEL); 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. 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_p
CVE-2026-90251
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90251
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"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",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/bluetooth/msft.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90251
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36616 · Revision 1
- Added to Heist Feed
- Publisher date