Bug 1860065 (CVE-2020-0305) - CVE-2020-0305 kernel: possible use-after-free due to a race condition in cdev_get of char_dev.c
Summary: CVE-2020-0305 kernel: possible use-after-free due to a race condition in cdev...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2020-0305
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: 1890062 1890063 1890064 1890065 1890066 1860066 1866323 1866324 1866325 1866326 1866327
Blocks: 1860068
TreeView+ depends on / blocked
 
Reported: 2020-07-23 16:19 UTC by Marian Rehak
Modified: 2021-02-16 19:38 UTC (History)
46 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A use-after-free flaw was found in the way the Linux kernel's filesystem subsystem handled a race condition in the chrdev_open function. This flaw allows a privileged local user to starve the resources, causing a denial of service or potentially escalating their privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
Clone Of:
Environment:
Last Closed: 2020-11-04 02:26:24 UTC

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System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2020:4431 0 None None None 2020-11-04 00:51:21 UTC
Red Hat Product Errata RHSA-2020:4609 0 None None None 2020-11-04 02:23:50 UTC

Description Marian Rehak 2020-07-23 16:19:46 UTC 
In cdev_get of char_dev.c, there is a possible use-after-free due to a race condition. This could lead to local escalation of privilege with System execution privileges needed.

Reference:

https://android.googlesource.com/kernel/common/+/68faa679b8be1a74e6663c21c3a9d25d3
Comment 1 Marian Rehak 2020-07-23 16:20:18 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1860066]
Comment 2 Justin M. Forbes 2020-07-23 19:06:58 UTC 
This was fixed for Fedora with the 5.4.12 stable kernel updates.
Comment 6 Alex 2020-08-05 11:14:38 UTC 
Mitigation:

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Comment 9 Petr Matousek 2020-08-06 11:23:31 UTC 
Statement:

This issue is rated as having Moderate impact because of the preconditions needed to trigger the issue (elevated/root privileges).
Comment 10 Petr Matousek 2020-08-06 11:23:39 UTC 
External References:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=68faa679b8be1a74e6663c21c3a9d25d32f1c079
Comment 12 errata-xmlrpc 2020-11-04 00:51:18 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4431 https://access.redhat.com/errata/RHSA-2020:4431
Comment 13 errata-xmlrpc 2020-11-04 02:23:47 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4609 https://access.redhat.com/errata/RHSA-2020:4609
Comment 14 Product Security DevOps Team 2020-11-04 02:26:24 UTC 
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-0305
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