Bug 1738705 (CVE-2018-20856) - CVE-2018-20856 kernel: Use-after-free in __blk_drain_queue() function in block/blk-core.c
Summary: CVE-2018-20856 kernel: Use-after-free in __blk_drain_queue() function in bloc...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2018-20856
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1739327 1739329 1739330 1738706 1739326 1739328 1753285
Blocks: 1738707
TreeView+ depends on / blocked
 
Reported: 2019-08-07 22:18 UTC by Pedro Sampaio
Modified: 2019-10-18 01:14 UTC (History)
49 users (show)

Fixed In Version:
Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the Linux kernel’s block driver implementation (blk_drain_queue() function) where a use-after-free condition could be triggered while draining the outstanding command queue in the systems block device subsystem. An attacker could use this flaw to crash the system or corrupt local memory, which may lead to privilege escalation.
Clone Of:
Environment:
Last Closed: 2019-10-16 06:51:20 UTC


Attachments (Terms of Use)


Links
System ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2019:3055 None None None 2019-10-15 17:46:11 UTC
Red Hat Product Errata RHSA-2019:3076 None None None 2019-10-15 17:48:47 UTC
Red Hat Product Errata RHSA-2019:3089 None None None 2019-10-16 07:57:12 UTC

Description Pedro Sampaio 2019-08-07 22:18:16 UTC
A flaw was found in the Linux kernels block driver implementation where a use-after-free condition could be triggered while draining the outstanding command queue in the systems block device subsystem.

A patient local attacker can use this flaw to corrupt memory, possibly crashing the system and possibly leading to privilege escalation.

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.7
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=54648cf1ec2d7f4b6a71767799c45676a138ca24
https://github.com/torvalds/linux/commit/54648cf1ec2d7f4b6a71767799c45676a138ca24

Comment 1 Pedro Sampaio 2019-08-07 22:20:48 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1738706]

Comment 4 Justin M. Forbes 2019-08-08 09:25:52 UTC
This was fixed in Fedora with the 4.18.7 stable kernel update.

Comment 5 Wade Mealing 2019-08-09 01:22:49 UTC
This flaw is rated as important due to possible memory corruption or additional flow on effects.

Comment 9 errata-xmlrpc 2019-10-15 17:46:07 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:3055 https://access.redhat.com/errata/RHSA-2019:3055

Comment 10 errata-xmlrpc 2019-10-15 17:48:44 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:3076 https://access.redhat.com/errata/RHSA-2019:3076

Comment 11 Product Security DevOps Team 2019-10-16 06:51:20 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-2018-20856

Comment 12 errata-xmlrpc 2019-10-16 07:57:09 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2019:3089 https://access.redhat.com/errata/RHSA-2019:3089


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