CVE-2021-47187

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxc3083c80b52c4e29b65ed838d2e66a91b13a3152 < a14d7038ea201c5526375becfc43b9ba281b1e82affected
LinuxLinuxc3083c80b52c4e29b65ed838d2e66a91b13a3152 < e52fecdd0c142b95c720683885b06ee3f0e065c8affected
LinuxLinuxc3083c80b52c4e29b65ed838d2e66a91b13a3152 < 118c826ef8b43efe0fda8faf419673707ee8c5e5affected
LinuxLinuxc3083c80b52c4e29b65ed838d2e66a91b13a3152 < 3f1dcaff642e75c1d2ad03f783fa8a3b1f56dd50affected
LinuxLinux5.3affected
LinuxLinux0 < 5.3unaffected
LinuxLinux5.4.162 <= 5.4.*unaffected
LinuxLinux5.10.82 <= 5.10.*unaffected
LinuxLinux5.15.5 <= 5.15.*unaffected
LinuxLinux5.16 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References