Description
An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5.
References (10)
Core 10
Core References
Patch, Vendor Advisory x_refsource_misc
https://xenbits.xen.org/xsa/advisory-331.html
Patch, Third Party Advisory x_refsource_misc
https://github.com/torvalds/linux/commit/073d0552ead5bfc7a3a9c01de590e924f11b5dd2
Patch, Vendor Advisory x_refsource_misc
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=073d0552ead5bfc7a3a9c01de590e924f11b5dd2
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3ZG6TZLD23QO3PV2AN2HB625ZX47ALTT/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6USZ4APZSBQDHGJLJMHW5JBN4QZV6SKZ/
Mailing List, Third Party Advisory vendor-advisory
x_refsource_fedora
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNF2R7FUT4IOJ2RIRGQ7X5R4F4FVVLSR/
Third Party Advisory vendor-advisory
x_refsource_gentoo
https://security.gentoo.org/glsa/202011-06
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html
Mailing List, Third Party Advisory mailing-list
x_refsource_mlist
http://www.openwall.com/lists/oss-security/2021/01/19/3
Scores
CVSS v3
4.7
EPSS
0.0006
EPSS Percentile
19.0%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Details
CWE
CWE-362
CWE-476
CWE-416
Status
published
Products (5)
debian/debian_linux
9.0
fedoraproject/fedora
31
fedoraproject/fedora
32
fedoraproject/fedora
33
linux/linux_kernel
< 5.9.1
Published
Oct 22, 2020
Tracked Since
Feb 18, 2026