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

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=073d0552ead5bfc7a3a9c01de590e924f11b5dd2

https://github.com/torvalds/linux/commit/073d0552ead5bfc7a3a9c01de590e924f11b5dd2

https://xenbits.xen.org/xsa/advisory-331.html

https://lists.fedoraproject.org/archives/list/[email protected]/message/3ZG6TZLD23QO3PV2AN2HB625ZX47ALTT/

https://lists.fedoraproject.org/archives/list/[email protected]/message/GNF2R7FUT4IOJ2RIRGQ7X5R4F4FVVLSR/

https://lists.fedoraproject.org/archives/list/[email protected]/message/6USZ4APZSBQDHGJLJMHW5JBN4QZV6SKZ/

https://security.gentoo.org/glsa/202011-06

https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html

https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html

http://www.openwall.com/lists/oss-security/2021/01/19/3

Details

Risk Information

CVSS v2

CVSS v3