Bug 1220747 (CVE-2021-47062) - VUL-0: CVE-2021-47062: kernel: KVM: SVM: potential NULL pointer dereference on vCPU iteration when encrypting VMSAs
Summary: VUL-0: CVE-2021-47062: kernel: KVM: SVM: potential NULL pointer dereference o...
Status: RESOLVED FIXED
Alias: CVE-2021-47062
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents (show other bugs)
Version: unspecified
Hardware: Other Other
: P5 - None : Normal
Target Milestone: ---
Assignee: Karasulli
QA Contact: Security Team bot
URL: https://smash.suse.de/issue/395873/
Whiteboard: CVSSv3.1:SUSE:CVE-2021-47062:4.4:(AV:...
Keywords:
Depends on:
Blocks:
 
Reported: 2024-03-01 10:01 UTC by SMASH SMASH
Modified: 2024-03-01 10:04 UTC (History)
2 users (show)

See Also:
Found By: Security Response Team
Services Priority:
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Blocker: ---
Marketing QA Status: ---
IT Deployment: ---

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Description SMASH SMASH 2024-03-01 10:01:55 UTC 
In the Linux kernel, the following vulnerability has been resolved:

KVM: SVM: Use online_vcpus, not created_vcpus, to iterate over vCPUs

Use the kvm_for_each_vcpu() helper to iterate over vCPUs when encrypting
VMSAs for SEV, which effectively switches to use online_vcpus instead of
created_vcpus.  This fixes a possible null-pointer dereference as
created_vcpus does not guarantee a vCPU exists, since it is updated at
the very beginning of KVM_CREATE_VCPU.  created_vcpus exists to allow the
bulk of vCPU creation to run in parallel, while still correctly
restricting the max number of max vCPUs.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-47062
https://git.kernel.org/stable/c/c36b16d29f3af5f32fc1b2a3401bf48f71cabee1
https://www.cve.org/CVERecord?id=CVE-2021-47062
https://git.kernel.org/stable/c/ba7bf5d6336aa9c0d977b161bfa420c56d46ee40
https://git.kernel.org/stable/c/bd0cced2ae93195668f983d443f7f17e8efd24d2
https://bugzilla.redhat.com/show_bug.cgi?id=2267171
Comment 1 Carlos López 2024-03-01 10:03:14 UTC 
Already fixed in cve/linux-5.14 and newer. Older branches are not affected. Closing.