Describe CVE-2021-47431.
What is CVE-2021-47431?
In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: fix gart.bo pin_count leak

gmc_v{9,10}_0_gart_disable() isn't called matched with
correspoding gart_enbale function in SRIOV case. This will
lead to gart.bo pin_count leak on driver unload..