Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (aspeed-g6-pwm-tach) Guard fan RPM calculation against divide-by-zero

Sashiko reports:

In the aspeed-g6-pwm-tacho driver, the aspeed_tach_val_to_rpm() function calculates the fan RPM using the tachometer value. However, it does not check if the tachometer value is zero before performing the division.

If the hardware reports a tachometer value of 0 (which can happen due to an extremely fast pulse, a stuck edge, or a hardware glitch), the calculated tach_div evaluates to 0. The subsequent call to do_div() with tach_div as the divisor triggers a divide-by-zero exception, leading to a kernel panic.

Check the divisor against zero to fix the problem.