CVE-2021-47187

In the Linux kernel, the following vulnerability has been resolved: arm64:
dts: qcom: msm8998: Fix CPU/L2 idle state latency and residency The
entry/exit latency and minimum residency in state for the idle states of
MSM8998 were …bad: first of all, for all of them the timings were written
for CPU sleep but the min-residency-us param was miscalculated (supposedly,
while porting this from downstream); Then, the power collapse states are
setting PC on both the CPU cluster and the L2 cache, which have different
timings: in the specific case of L2 the times are higher so these ones
should be taken into account instead of the CPU ones. This parameter
misconfiguration was not giving particular issues because on MSM8998 there
was no CPU scaling at all, so cluster/L2 power collapse was rarely (if
ever) hit. When CPU scaling is enabled, though, the wrong timings will
produce SoC unstability shown to the user as random, apparently error-less,
sudden reboots and/or lockups. This set of parameters are stabilizing the
SoC when CPU scaling is ON and when power collapse is frequently hit.