Bug 1729933 (CVE-2019-10639) - CVE-2019-10639 Kernel: net: using kernel space address bits to derive IP ID may potentially break KASLR
Summary: CVE-2019-10639 Kernel: net: using kernel space address bits to derive IP ID m...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2019-10639
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: 1729934 1737436 1737437 1737438 1737439 1737440 1828466 1828467
Blocks: 1729937
TreeView+ depends on / blocked
 
Reported: 2019-07-15 11:16 UTC by Marian Rehak
Modified: 2023-10-06 18:25 UTC (History)
46 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
A flaw was found in the way the Linux kernel derived the IP ID field from a partial kernel space address returned by a net_hash_mix() function. A remote user could observe this IP ID field to extract the kernel address bits used to derive its value, which may result in leaking the hash key and potentially defeating KASLR.
Clone Of:
Environment:
Last Closed: 2020-03-31 22:34:36 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2020:2052 0 None None None 2020-05-11 12:53:43 UTC
Red Hat Product Errata RHBA-2020:2626 0 None None None 2020-06-19 01:49:44 UTC
Red Hat Product Errata RHSA-2020:1016 0 None None None 2020-03-31 19:11:49 UTC
Red Hat Product Errata RHSA-2020:1070 0 None None None 2020-03-31 19:20:59 UTC
Red Hat Product Errata RHSA-2020:1567 0 None None None 2020-04-28 15:24:57 UTC
Red Hat Product Errata RHSA-2020:1769 0 None None None 2020-04-28 15:51:19 UTC
Red Hat Product Errata RHSA-2020:2522 0 None None None 2020-06-11 02:10:13 UTC

Description Marian Rehak 2019-07-15 11:16:13 UTC 
When IP packet fragmentation is ON, IP Identification(ID) field of the IP header 
is used, during packet reassembly on the destination host, to identify fragments 
which belong to the same packet. IP ID field is required to be unique and same 
across all fragments of an IP packet. IP packet fragments are identified by a 
tuple with following fields

    (source address|destination address|protocol|IP-ID)

The Linux kernel derived this IP ID field from partial kernel space address 
returned by net_hash_mix() function, which is then used with a hash function to 
compute the IP ID field.

A remote user could observe this IP ID field to deduce the kernel space address 
bits used to derive its value. Thus leaking the hash key and potentially 
defeating KASLR.

Upstream fix:
-------------
  -> https://git.kernel.org/linus/355b98553789b646ed97ad801a619ff898471b92

Issue introduced by:
--------------------
  -> https://git.kernel.org/linus/b6a7719aedd7e5c0f2df7641aa47386111682df4
  -> https://git.kernel.org/linus/5a352dd0a3aac03b443c94828dfd7144261c8636
Comment 1 Marian Rehak 2019-07-15 11:16:29 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1729934]
Comment 2 Prasad Pandit 2019-07-28 08:11:16 UTC 
External References:

https://arxiv.org/pdf/1906.10478.pdf
Comment 4 Prasad Pandit 2019-08-06 06:58:51 UTC 
Statement:

This issue does not affect the versions of Linux kernel as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6.

This issue affects the version of Linux kernel as shipped with Red Hat Enterprise Linux 7,  8 and Red Hat Enterprise MRG 2. Future kernel updates for Red Hat Enterprise Linux 7, 8 and Red Hat Enterprise MRG 2 may address this issue.
Comment 5 errata-xmlrpc 2020-03-31 19:11:46 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:1016 https://access.redhat.com/errata/RHSA-2020:1016
Comment 6 errata-xmlrpc 2020-03-31 19:20:56 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:1070 https://access.redhat.com/errata/RHSA-2020:1070
Comment 7 Product Security DevOps Team 2020-03-31 22:34:36 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-2019-10639
Comment 10 errata-xmlrpc 2020-04-28 15:24:54 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:1567 https://access.redhat.com/errata/RHSA-2020:1567
Comment 11 errata-xmlrpc 2020-04-28 15:51:15 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:1769 https://access.redhat.com/errata/RHSA-2020:1769
Comment 12 errata-xmlrpc 2020-06-11 02:10:10 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7.7 Extended Update Support

Via RHSA-2020:2522 https://access.redhat.com/errata/RHSA-2020:2522
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