Bug 1790063 (CVE-2019-20054) - CVE-2019-20054 kernel: Null pointer dereference in drop_sysctl_table() in fs/proc/proc_sysctl.c
Summary: CVE-2019-20054 kernel: Null pointer dereference in drop_sysctl_table() in fs/...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2019-20054
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1790064 1795518 1795519 1795520 1795521 1795522 1795523 1795828
Blocks: 1790067
TreeView+ depends on / blocked
 
Reported: 2020-01-11 15:16 UTC by Pedro Sampaio
Modified: 2020-11-04 02:22 UTC (History)
45 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the Linux kernel’s implementation of dropping sysctl entries. A local attacker who has access to load modules on the system can trigger a condition during module load failure and panic the system.
Clone Of:
Environment:
Last Closed: 2020-04-16 16:32:05 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2020:4416 0 None None None 2020-10-29 15:10:03 UTC
Red Hat Product Errata RHBA-2020:4417 0 None None None 2020-10-29 15:08:32 UTC
Red Hat Product Errata RHBA-2020:4418 0 None None None 2020-10-29 15:14:00 UTC
Red Hat Product Errata RHBA-2020:4419 0 None None None 2020-10-29 15:12:25 UTC
Red Hat Product Errata RHBA-2020:4420 0 None None None 2020-10-29 15:51:20 UTC
Red Hat Product Errata RHSA-2020:1493 0 None None None 2020-04-16 14:38:53 UTC
Red Hat Product Errata RHSA-2020:4060 0 None None None 2020-09-29 20:53:05 UTC
Red Hat Product Errata RHSA-2020:4062 0 None None None 2020-09-29 18:59:04 UTC
Red Hat Product Errata RHSA-2020:4431 0 None None None 2020-11-04 00:50:25 UTC
Red Hat Product Errata RHSA-2020:4609 0 None None None 2020-11-04 02:22:32 UTC

Description Pedro Sampaio 2020-01-11 15:16:10 UTC 
A flaw was found in the Linux kernels implementation of dropping sysctl entries.  The case where insert_header() fails the parent pointer may still be set to null and then accessed.

This operation is usually invoked during a module load (a local, privileged operation) and requires a failure mode to take place.  It is unlikely to be able to be used successfully as an attack vector. 



Upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23da9588037ecdd4901db76a5b79a42b529c4ec3
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=89189557b47b35683a27c80ee78aef18248eefb4

References:

https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.11
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.6
Comment 1 Pedro Sampaio 2020-01-11 15:16:40 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1790064]
Comment 2 Justin M. Forbes 2020-01-13 12:58:59 UTC 
This was fixed for Fedora with the 5.0.6 stable updates.
Comment 9 errata-xmlrpc 2020-04-16 14:38:50 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:1493 https://access.redhat.com/errata/RHSA-2020:1493
Comment 10 Product Security DevOps Team 2020-04-16 16:32:05 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-2019-20054
Comment 11 errata-xmlrpc 2020-09-29 18:59:00 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4062 https://access.redhat.com/errata/RHSA-2020:4062
Comment 12 errata-xmlrpc 2020-09-29 20:53:01 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:4060 https://access.redhat.com/errata/RHSA-2020:4060
Comment 28 errata-xmlrpc 2020-11-04 00:50:23 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 29 errata-xmlrpc 2020-11-04 02:22:30 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
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