CVE-2021-47407: KVM: x86: Handle SRCU initialization failure during page track init
Vulnerability summary
CVE-2021-47407 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.3% of scored vulnerabilities.
Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 8 · Related 8Timeline
- 21-05-2024PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Handle SRCU initialization failure during page track init Check the return of init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller. [Move the call towards the beginning of kvm_arch_init_vm. - Paolo]
CVSS metrics
4 scores · 3 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.25%
Chance of exploitation in the next 30 days
Percentile
16%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.25% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu91 products
- linuxAll versions (No fix recorded)
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded)
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 0eb05bf290cfe8610d9680b49abef37febd1c38a, < deb2949417677649e2413266d7ce8c2ff73952b4 | ≥ 0eb05bf290cfe8610d9680b49abef37febd1c38a, < 4664318f73e496cd22c71b10888e75434a123e23 | ≥ 0eb05bf290cfe8610d9680b49abef37febd1c38a, < eb7511bf9182292ef1df1082d23039e856d1ddfb | 4.6
- linux_kernel< 5.10.71 | ≥ 5.11, < 5.14.10 | 5.15:rc1 | 5.15:rc2 | 5.15:rc3
Debian1 product
- linux< 5.14.12-1
3 vendors · 94 products
