CVE-2021-47475: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

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 vmk80xx_cnt_insn_read() for the VMK8061_MODEL) 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.

Affected products

• Linux Linux Kernel: from 2.6.31, before 4.4.292 (fixed in 4.4.292); from 4.5, before 4.9.290 (fixed in 4.9.290); from 4.10, before 4.14.255 (fixed in 4.14.255); from 4.15, before 4.19.217 (fixed in 4.19.217); from 4.20, before 5.4.159 (fixed in 5.4.159); from 5.5, before 5.10.79 (fixed in 5.10.79); …

Published 2024-05-22. Last modified 2026-06-17.