Bug 1905676 (CVE-2020-29571) - CVE-2020-29571 xen: FIFO event channels control structure ordering
Summary: CVE-2020-29571 xen: FIFO event channels control structure ordering
Keywords:
Status: CLOSED UPSTREAM
Alias: CVE-2020-29571
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1908089
Blocks: 1903644
TreeView+ depends on / blocked
 
Reported: 2020-12-08 19:44 UTC by Guilherme de Almeida Suckevicz
Modified: 2021-02-16 18:46 UTC (History)
4 users (show)

Fixed In Version:
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Environment:
Last Closed: 2020-12-15 22:20:15 UTC


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Description Guilherme de Almeida Suckevicz 2020-12-08 19:44:55 UTC
A bounds check common to most operation time functions specific to FIFO
event channels depends on the CPU observing consistent state.  While the
producer side uses appropriately ordered writes, the consumer side isn't
protected against re-ordered reads, and may hence end up de-referencing
a NULL pointer.

Comment 1 Guilherme de Almeida Suckevicz 2020-12-15 20:02:09 UTC
External References:

https://www.openwall.com/lists/oss-security/2020/12/15/16

Comment 2 Guilherme de Almeida Suckevicz 2020-12-15 20:02:22 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1908089]

Comment 3 Product Security DevOps Team 2020-12-15 22:20:15 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.


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