Bug 2266406 (CVE-2021-46907) - CVE-2021-46907 kernel: KVM: internal.ndata could be updated by the user process at anytime
Summary: CVE-2021-46907 kernel: KVM: internal.ndata could be updated by the user proce...
Keywords:
Status: NEW
Alias: CVE-2021-46907
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2266409
Blocks: 2266369
TreeView+ depends on / blocked
 
Reported: 2024-02-27 18:49 UTC by Rohit Keshri
Modified: 2024-03-26 18:31 UTC (History)
50 users (show)

Fixed In Version:
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A flaw was found in KVM VMX in the Linux Kernel, where ndata' could be updated by the user process at any time
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Description Rohit Keshri 2024-02-27 18:49:02 UTC 
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
Comment 1 Rohit Keshri 2024-02-27 18:56:44 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 2266409]
Comment 3 Justin M. Forbes 2024-02-27 23:12:31 UTC 
This was fixed for Fedora with the 5.11.16 stable kernel updates.
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