CVE-2021-47475

Source
https://nvd.nist.gov/vuln/detail/CVE-2021-47475
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47475.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2021-47475
Downstream
Related
Published
2024-05-22T09:15:09Z
Modified
2025-09-24T18:58:58Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

comedi: vmk80xx: fix transfer-buffer overflows

The driver uses endpoint-sized USB transfer buffers but up until recently had no sanity checks on the sizes.

Commit e1f13c879a7c ("staging: comedi: check validity of wMaxPacketSize of usb endpoints found") inadvertently fixed NULL-pointer dereferences when accessing the transfer buffers in case a malicious device has a zero wMaxPacketSize.

Make sure to allocate buffers large enough to handle also the other accesses that are done without a size check (e.g. byte 18 in vmk80xxcntinsnread() for the VMK8061MODEL) to avoid writing beyond the buffers, for example, when doing descriptor fuzzing.

The original driver was for a low-speed device with 8-byte buffers. Support was later added for a device that uses bulk transfers and is presumably a full-speed device with a maximum 64-byte wMaxPacketSize.

References

Affected packages