{"id":"CVE-2020-29569","details":"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-\u003exenblkd 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.","modified":"2026-03-13T00:40:31.822710Z","published":"2020-12-15T17:15:14.707Z","related":["SUSE-SU-2021:0347-1","SUSE-SU-2021:0348-1","SUSE-SU-2021:0353-1","SUSE-SU-2021:0354-1","SUSE-SU-2021:0359-1","SUSE-SU-2021:0362-1","SUSE-SU-2021:0367-1","SUSE-SU-2021:0377-1","SUSE-SU-2021:0386-1","SUSE-SU-2021:0408-1","SUSE-SU-2021:0427-1","SUSE-SU-2021:0433-1","SUSE-SU-2021:0434-1","SUSE-SU-2021:0437-1","SUSE-SU-2021:0438-1","SUSE-SU-2021:0452-1","SUSE-SU-2021:0532-1","openSUSE-SU-2021:0075-1","openSUSE-SU-2021:0241-1"],"references":[{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202107-30"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20210205-0001/"},{"type":"ADVISORY","url":"https://www.debian.org/security/2021/dsa-4843"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/02/msg00018.html"},{"type":"ADVISORY","url":"https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html"},{"type":"FIX","url":"https://xenbits.xenproject.org/xsa/advisory-350.html"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2020-29569.json","unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"4.14.1"}]},{"events":[{"introduced":"4.1.44"},{"fixed":"4.2"}]},{"events":[{"introduced":"4.4.80"},{"fixed":"4.4.254"}]},{"events":[{"introduced":"4.9.36"},{"fixed":"4.9.249"}]},{"events":[{"introduced":"4.11.9"},{"fixed":"4.12"}]},{"events":[{"introduced":"4.12"},{"fixed":"4.14.213"}]},{"events":[{"introduced":"4.15"},{"fixed":"4.19.164"}]},{"events":[{"introduced":"4.20"},{"fixed":"5.4.86"}]},{"events":[{"introduced":"5.5"},{"fixed":"5.10.4"}]},{"events":[{"introduced":"0"},{"last_affected":"9.0"}]},{"events":[{"introduced":"0"},{"last_affected":"10.0"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"}]}