In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Don't use vcpu->run->internal.ndata as an array index __vmx_handle_exit() uses vcpu->run->internal.ndata as an index for an array access. Since vcpu->run is (can be) mapped to a user address space with a writer permission, the 'ndata' could be updated by the user process at anytime (the user process can set it to outside the bounds of the array). So, it is not safe that __vmx_handle_exit() uses the 'ndata' that way. https://git.kernel.org/stable/c/04c4f2ee3f68c9a4bf1653d15f1a9a435ae33f7a https://git.kernel.org/stable/c/7f64753835a78c7d2cc2932a5808ef3b7fd4c050 https://git.kernel.org/stable/c/ce541d7b59566a0d94c7c99bfb5d34b050e6af70
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 2266409]
This was fixed for Fedora with the 5.11.16 stable kernel updates.
The result of automatic check (that is developed by Alexander Larkin) for this CVE-2021-46907 is: CHECK Maybe valid. Check manually. with impact LOW (that is an approximation based on flags VIRT INIT SIMPLEFIX ; these flags parsed automatically based on patch data). Such automatic check happens only for Low/Moderates (and only when not from reporter, but parsing already existing CVE). Highs always checked manually (I check it myself and then we check it again in Remediation team). In rare cases some of the Moderates could be increased to High later.