misc: nsm: bound the device-reported response length
In the Linux kernel, the following vulnerability has been resolved: misc: nsm: bound the device-reported response length nsm_sendrecv_msg_locked() stores the virtqueue used-ring length reported by the NSM device into msg->resp.len without bounding it to the response buffer. A malicious or buggy backend can report a length larger than the response buffer; parse_resp_raw() then copies that many bytes out of the fixed buffer to user space, disclosing adjacent kernel heap (an out-of-bounds read). The request path already floors its length in fill_req_raw(); the response path lacks the symmetric check. Clamp the stored length to the size of the response buffer. Well-behaved devices report no more than the posted buffer size, so conforming traffic is unaffected.
CVE-2026-89743
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-2026-89743
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": "b9873755a6c8ccfce79094c4dce9efa3ecb1a749",
"lessThan": "339f19b9a6171289b0e797deb8bda80b9a1fcc30",
"versionType": "git"
},
{
"status": "affected",
"version": "b9873755a6c8ccfce79094c4dce9efa3ecb1a749",
"lessThan": "29e634a18957acda11383a15ab98a91c4ae9e294",
"versionType": "git"
},
{
"status": "affected",
"version": "b9873755a6c8ccfce79094c4dce9efa3ecb1a749",
"lessThan": "2aa0fb9c96f894a9c179a48e7522ea6705800adf",
"versionType": "git"
},
{
"status": "affected",
"version": "b9873755a6c8ccfce79094c4dce9efa3ecb1a749",
"lessThan": "808e530654a5354e6df78863a5d61e4d44e67235",
"versionType": "git"
}
],
"programFiles": [
"drivers/misc/nsm.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.109",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.50",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/misc/nsm.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89743
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35217 · Revision 1
- Added to Heist Feed
- Publisher date