Bug 1905636 (CVE-2020-29569) - CVE-2020-29569 xen: Use after free triggered by block frontend in Linux blkback (XSA-350)
Summary: CVE-2020-29569 xen: Use after free triggered by block frontend in Linux blkba...
Alias: CVE-2020-29569
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 1908082
Blocks: 1903644
TreeView+ depends on / blocked
Reported: 2020-12-08 18:00 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-03-04 22:02 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
Clone Of:
Last Closed: 2020-12-15 22:19:47 UTC

Attachments (Terms of Use)

Description Guilherme de Almeida Suckevicz 2020-12-08 18:00:05 UTC
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 toggle between the states
connect and disconnect.

As a consequence, the block backend may re-use a pointer after it was

Comment 1 Guilherme de Almeida Suckevicz 2020-12-15 19:53:52 UTC
External References:


Comment 2 Guilherme de Almeida Suckevicz 2020-12-15 19:54:06 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1908082]

Comment 3 Product Security DevOps Team 2020-12-15 22:19:47 UTC
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.

Comment 4 Justin M. Forbes 2021-03-04 22:02:00 UTC
This was fixed for Fedora with the 5.10.4 stable kernel updates.

Note You need to log in before you can comment on or make changes to this bug.