cxl/mbox: Clamp mailbox output allocation to the payload size
In the Linux kernel, the following vulnerability has been resolved: cxl/mbox: Clamp mailbox output allocation to the payload size CXL_MEM_SEND_COMMAND bounds the user's in.size to the mailbox payload size but leaves out.size unbounded, then cxl_mbox_cmd_ctor() calls kvzalloc(out.size). A large out.size drives a huge allocation, above INT_MAX it WARNs and taints, and with panic_on_warn=1 it panics. The transport __cxl_pci_mbox_send_cmd() already clamps the response copy to min(out.size, payload_size, device len), so the output buffer is never written beyond payload_size. Clamp the allocation to payload_size too, matching the RAW path.
CVE-2026-93186
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-2026-93186
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": "583fa5e71caeb79e04e477e9837e2f7fa53b71e4",
"lessThan": "d2d40574b9b272ade32d0d77b140d990e7547f5f",
"versionType": "git"
},
{
"status": "affected",
"version": "583fa5e71caeb79e04e477e9837e2f7fa53b71e4",
"lessThan": "f5d2bbf0300f46307948864fbb97bce5097f4fe2",
"versionType": "git"
},
{
"status": "affected",
"version": "583fa5e71caeb79e04e477e9837e2f7fa53b71e4",
"lessThan": "31d4841eca7c4b75751ca96d24339e19303337f2",
"versionType": "git"
},
{
"status": "affected",
"version": "583fa5e71caeb79e04e477e9837e2f7fa53b71e4",
"lessThan": "b4e11c731d6bee3b87315e055a1ca417c92dc1fc",
"versionType": "git"
},
{
"status": "affected",
"version": "583fa5e71caeb79e04e477e9837e2f7fa53b71e4",
"lessThan": "8a13db9f899d149c3aab24abcb668121cfda5a4f",
"versionType": "git"
}
],
"programFiles": [
"drivers/cxl/core/mbox.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"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": [
"drivers/cxl/core/mbox.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-93186
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #48728 · Revision 1
- Added to Heist Feed
- Publisher date