iio: adc: tsc2046: fix memory corruption by preventing array overflow

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: iio: adc: tsc2046: fix memory corruption by preventing array overflow On one side we have indio_dev->num_channels includes all physical channels + timestamp channel. On other side we have an array allocated only for physical channels. So, fix memory corruption by ARRAY_SIZE() instead of num_channels variable. Note the first case is a cleanup rather than a fix as the software timestamp channel bit in active_scanmask is never set by the IIO core.

References

• https://git.kernel.org/stable/c/0cb9b2f73c182d242a640e512f4785c7c504512f
• https://git.kernel.org/stable/c/082d2c047b0d305bb0b6e9f9d671a09470e2db2d
• https://git.kernel.org/stable/c/b7a78a8adaa8849c02f174d707aead0f85dca0da