Bug 1528323 (CVE-2017-17806)

Summary:	CVE-2017-17806 kernel: HMAC implementation does not validate that the underlying cryptographic hash algorithm is unkeyed allowing local attackers to cause denial-of-service
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	airlied, ajax, aquini, bhu, blc, bskeggs, dhoward, ewk, fhrbata, hdegoede, hkrzesin, hwkernel-mgr, iboverma, ichavero, itamar, jarodwilson, jforbes, jglisse, jkacur, john.j5live, jonathan, josef, jross, jwboyer, kernel-maint, kernel-mgr, labbott, lgoncalv, linville, matt, mchehab, mcressma, mjg59, mlangsdo, nmurray, plougher, rt-maint, rvrbovsk, skozina, slawomir, steved, vdronov, williams, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel 4.14.8	Doc Type:	Bug Fix
Doc Text:	The HMAC implementation (crypto/hmac.c) in the Linux kernel, before 4.14.8, does not validate that the underlying cryptographic hash algorithm is unkeyed. This allows a local attacker, able to use the AF_ALG-based hash interface (CONFIG_CRYPTO_USER_API_HASH) and the SHA-3 hash algorithm (CONFIG_CRYPTO_SHA3), to cause a kernel stack buffer overflow by executing a crafted sequence of system calls that encounter a missing SHA-3 initialization.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 03:34:44 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1528337, 1528343, 1544462
Bug Blocks:	1528324

Description Adam Mariš 2017-12-21 14:40:03 UTC

The HMAC implementation (crypto/hmac.c) in the Linux kernel before 4.14.8 does not validate that the underlying cryptographic hash algorithm is unkeyed, allowing a local attacker able to use the AF_ALG-based hash interface (CONFIG_CRYPTO_USER_API_HASH) and the SHA-3 hash algorithm (CONFIG_CRYPTO_SHA3) to cause a kernel stack buffer overflow by executing a crafted sequence of system calls that encounter a missing SHA-3 initialization.

References:

https://marc.info/?t=151192100500002&r=1&w=2

An upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=af3ff8045bbf3e32f1a448542e73abb4c8ceb6f1

Comment 1 Adam Mariš 2017-12-21 15:12:39 UTC

Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1528337]

Comment 3 Justin M. Forbes 2018-01-29 17:56:14 UTC

This was fixed for Fedora with the 4.14.8 stable updates.

Comment 8 Eric Christensen 2018-02-13 17:01:06 UTC

Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5, 6, and 7, its real-time kernel and Red Hat Enterprise MRG 2.

This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 7 for ARM 64 and Red Hat Enterprise Linux 7 for Power 9 LE. Future Linux kernel updates for the respective releases may address this issue.

Comment 9 errata-xmlrpc 2018-10-30 08:56:49 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:2948 https://access.redhat.com/errata/RHSA-2018:2948