Problem Description:

The kernel driver for /dev/midistat implements a handler for read(2). This handler is not thread-safe, and a multi-threaded program can exploit races in the handler to cause it to copy out kernel memory outside the boundaries of midistat's data buffer.

Impact:

The races allow a program to read kernel memory within a 4GB window centered at midistat's data buffer. The buffer is allocated each time the device is opened, so an attacker is not limited to a static 4GB region of memory.

On 32-bit platforms, an attempt to trigger the race may cause a page fault in kernel mode, leading to a panic.

ge 12.0 lt 12.0_10

ge 11.3 lt 11.3_3

ge 11.2 lt 11.2_14