CVE-2020-29569
highpriority · track · 35EPSS 0.004 · 34 %ileEURUUSEPSS · scored 2026-10-28
An issue was discovered in the Linux kernel through 5.10.1, as used with Xen through 4.14.x. The Linux kernel PV block backend expects the kernel thread handler to reset ring->xenblkd to NULL when stopped. However, the handler may not have time to run if the frontend quickly toggles between the states connect and disconnect. As a consequence, the block backend may re-use a pointer after it was freed. A misbehaving guest can trigger a dom0 crash by continuously connecting / disconnecting a block frontend. Privilege escalation and information leaks cannot be ruled out. This only affects systems with a Linux blkback.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (27)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
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references (32)
External citations — patches, advisories, analysis.
- https://lists.debian.org/debian-lts-announce/2021/02/msg00018.htmlcnnvd
- https://lists.debian.org/debian-lts-announce/2021/03/msg00010.htmlcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2020-29569cnnvd
- https://packetstormsecurity.com/files/161552/Ubuntu-Security-Notice-USN-4749-1.htmlcnnvd
- https://packetstormsecurity.com/files/161810/Ubuntu-Security-Notice-USN-4876-1.htmlcnnvd
- https://packetstormsecurity.com/files/163474/Gentoo-Linux-Security-Advisory-202107-30.htmlcnnvd
- https://security.gentoo.org/glsa/202107-30cnnvd
- https://security.netapp.com/advisory/ntap-20210205-0001/cnnvd
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