HID: mcp2221: validate report size in mcp2221_raw_event()
mcp2221_raw_event() never validates the size of incoming HID reports.
In the MCP2221_I2C_GET_DATA path it trusts the device-supplied data[3]
as the copy length without checking that 4 + data[3] bytes actually
exist in the received report. A malicious or misbehaving USB device can
send a short report with a large data[3], causing the memcpy to read
past the valid report data in the HID transfer buffer and leak
uninitialized kernel memory back to userspace through the I2C/SMBus
read path.
Add a minimum size check at entry and validate that the source range
fits within the received report before the copy.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
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| Linux | Linux | affected |
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Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Sat, 12 Sep 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-119 CWE-200 |
Fri, 11 Sep 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: HID: mcp2221: validate report size in mcp2221_raw_event() mcp2221_raw_event() never validates the size of incoming HID reports. In the MCP2221_I2C_GET_DATA path it trusts the device-supplied data[3] as the copy length without checking that 4 + data[3] bytes actually exist in the received report. A malicious or misbehaving USB device can send a short report with a large data[3], causing the memcpy to read past the valid report data in the HID transfer buffer and leak uninitialized kernel memory back to userspace through the I2C/SMBus read path. Add a minimum size check at entry and validate that the source range fits within the received report before the copy. | |
| Title | HID: mcp2221: validate report size in mcp2221_raw_event() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-11T19:45:19.420Z
Reserved: 2026-09-11T19:38:34.736Z
Link: CVE-2026-89621
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-11T20:19:47.397
Modified: 2026-09-11T20:19:47.397
Link: CVE-2026-89621
Redhat
No data.
OpenCVE Enrichment
Updated: 2026-09-12T09:15:12Z