cxl/features: bound fwctl command payload to the input buffer
In the Linux kernel, the following vulnerability has been resolved: cxl/features: bound fwctl command payload to the input buffer fwctl_cmd_rpc() copies cmd->in_len bytes into inbuf = kvzalloc(cmd->in_len) and passes inbuf and in_len to ->fw_rpc(). The CXL callback cxlctl_fw_rpc() ignores in_len and never checks the user-controlled op_size against it. cxlctl_set_feature() bounds op_size only from below (op_size <= sizeof(feat_in->hdr)) and then reads op_size - sizeof(hdr) bytes from feat_in->feat_data via cxl_set_feature(). With a small in_len and a large op_size the first memcpy() already reads past the kvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox payload and sent to the device, and a large enough op_size can walk into unmapped memory and oops the kernel. The Get paths pin op_size to a fixed size but likewise read the input struct without checking in_len. Reject, at the single dispatch point, any request whose fixed header plus op_size does not fit in the copied-in buffer. The lower-bound test guards the subtraction and ensures op_size was copied in before it is read.
CVE-2026-89571
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-2026-89571
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": "eb5dfcb9e36d0e46089fec777d911313c1876fa3",
"lessThan": "14d52c15d5d99477b20a2d61fe36f347080da6cd",
"versionType": "git"
},
{
"status": "affected",
"version": "eb5dfcb9e36d0e46089fec777d911313c1876fa3",
"lessThan": "d8957545fe96f7905791c937758ebfc1ae1e5b17",
"versionType": "git"
},
{
"status": "affected",
"version": "eb5dfcb9e36d0e46089fec777d911313c1876fa3",
"lessThan": "f687394af983df5660b6afae7e0d06969f3af206",
"versionType": "git"
}
],
"programFiles": [
"drivers/cxl/core/features.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.15",
"versionType": "semver"
},
{
"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/cxl/core/features.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89571
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35082 · Revision 1
- Added to Heist Feed
- Publisher date