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.
https://git.kernel.org/stable/c/f73b29819c6314c0ba8b7d5892dfb03487424bee
https://git.kernel.org/stable/c/f4d28d8b9b0e7c4ae04214b8d7e0b0466ec6bcaf
https://git.kernel.org/stable/c/a08799d3e8c8088640956237c183f83463c39668
https://git.kernel.org/stable/c/9625b00cac6630479c0ff4b9fafa88bee636e1f0
https://git.kernel.org/stable/c/7b6552719c0ccbbea29dde4be141da54fdb5877e
https://git.kernel.org/stable/c/75ed985bd6c8ac1d4e673e93ea9d96c9908c1d37
https://git.kernel.org/stable/c/5880afefe0cb9b2d5e801816acd58bfe91a96981
https://git.kernel.org/stable/c/1e97743fd180981bef5f01402342bb54bf1c6366
https://git.kernel.org/stable/c/077259f5e777c3c8821f6b41dee709fcda27306b