CVE-2021-47055: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: mtd: require write permissions for locking and badblock ioctls MEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require write permission. Depending on the hardware MEMLOCK might even be write-once, e.g. for SPI-NOR flashes with their WP# tied to GND. OTPLOCK is always write-once. MEMSETBADBLOCK modifies the bad block table.

Affected products

• Linux Linux Kernel: from 4.4.233, before 4.4.269 (fixed in 4.4.269); from 4.9.233, before 4.9.269 (fixed in 4.9.269); from 4.14.194, before 4.14.233 (fixed in 4.14.233); from 4.19.139, before 4.19.191 (fixed in 4.19.191); from 5.4.58, before 5.4.119 (fixed in 5.4.119); from 5.9, before 5.10.37 (fixed in 5.10.37); …

Published 2024-02-29. Last modified 2026-08-04.