CVE-2021-47055

En el kernel de Linux se ha solucionado la siguiente vulnerabilidad: mtd: requiere permisos de escritura para bloqueo y badblock ioctls MEMLOCK, MEMUNLOCK y OTPLOCK modifican los bits de protección. Por lo tanto, requiere permiso de escritura. Dependiendo del hardware, MEMLOCK podría incluso ser de escritura única, por ejemplo, para flashes SPI-NOR con su WP# vinculado a GND. OTPLOCK siempre se escribe una vez. MEMSETBADBLOCK modifica la tabla de bloques defectuosos.

A flaw was found in the Linux Kernel, requiring write permissions for locking and badblock ioctls, as they modify protection bits.

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.

Lyu Tao discovered that the NFS implementation in the Linux kernel did not properly handle requests to open a directory on a regular file. A local attacker could use this to expose sensitive information. Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system.