usb: class: cdc-wdm: fix reordering issue in read code path
Quoting the bug report:
Due to compiler optimization or CPU out-of-order execution, the
desc->length update can be reordered before the memmove. If this
happens, wdm_read() can see the new length and call copy_to_user() on
uninitialized memory. This also violates LKMM data race rules [1].
Fix it by using WRITE_ONCE and memory barriers.
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No vendor fix or workaround currently provided.
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Tracking
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Sat, 09 May 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-254 |
Sat, 09 May 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-366 | |
| References |
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| Metrics |
threat_severity
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cvssV3_1
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Fri, 08 May 2026 18:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-254 |
Fri, 08 May 2026 14:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: usb: class: cdc-wdm: fix reordering issue in read code path Quoting the bug report: Due to compiler optimization or CPU out-of-order execution, the desc->length update can be reordered before the memmove. If this happens, wdm_read() can see the new length and call copy_to_user() on uninitialized memory. This also violates LKMM data race rules [1]. Fix it by using WRITE_ONCE and memory barriers. | |
| Title | usb: class: cdc-wdm: fix reordering issue in read code path | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T22:24:22.781Z
Reserved: 2026-05-01T14:12:56.009Z
Link: CVE-2026-43427
No data.
Status : Awaiting Analysis
Published: 2026-05-08T15:16:54.867
Modified: 2026-05-12T14:10:27.343
Link: CVE-2026-43427
OpenCVE Enrichment
Updated: 2026-05-09T16:00:13Z