Bug 1528312 (CVE-2017-17805)

Summary: CVE-2017-17805 kernel: Salsa20 encryption algorithm does not correctly handle zero-length inputs allowing local attackers to cause denial-of-service
Product: [Other] Security Response Reporter: Adam Mariš <amaris>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: airlied, ajax, aquini, bhu, blc, bskeggs, dhoward, dominik.mierzejewski, 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 Salsa20 encryption algorithm in the Linux kernel, before 4.14.8, does not correctly handle zero-length inputs. This allows a local attacker the ability to use the AF_ALG-based skcipher interface to cause a denial of service (uninitialized-memory free and kernel crash) or have an unspecified other impact by executing a crafted sequence of system calls that use the blkcipher_walk API. Both the generic implementation (crypto/salsa20_generic.c) and x86 implementation (arch/x86/crypto/salsa20_glue.c) of Salsa20 are vulnerable.
Story Points: ---
Clone Of: Environment:
Last Closed: 2019-06-08 03:34:41 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, 1528342, 1543980, 1543981, 1543982, 1543983, 1543984, 1740280, 1740281, 1740282    
Bug Blocks: 1528313    

Description Adam Mariš 2017-12-21 14:09:56 UTC
The Salsa20 encryption algorithm in the Linux kernel before 4.14.8 does not correctly handle zero-length inputs, allowing a local attacker able to use the AF_ALG-based skcipher interface to cause a denial of service (uninitialized-memory free and kernel crash) or have unspecified other impact by executing a crafted sequence of system calls that use the blkcipher_walk API. Both the generic implementation (crypto/salsa20_generic.c) and x86 implementation (arch/x86/crypto/salsa20_glue.c) of Salsa20 are vulnerable.

An upstream patch:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ecaaab5649781c5a0effdaf298a925063020500e

Comment 1 Adam Mariš 2017-12-21 15:13:46 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1528337]

Comment 3 Justin M. Forbes 2018-01-29 17:55:34 UTC
This was fixed for Fedora with the 4.14.8 stable updates.

Comment 8 Eric Christensen 2018-02-12 14:30:52 UTC
Statement:

This issue does not affect the Linux kernel packages as shipped with Red Hat Enterprise Linux 5 as the code with the flaw is not present in the products listed.

This issue affects the versions of the Linux kernel as shipped with Red Hat Enterprise Linux 6, 7, its real-time kernel, Red Hat Enterprise MRG 2, 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 07:30:53 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:3083 https://access.redhat.com/errata/RHSA-2018:3083

Comment 10 errata-xmlrpc 2018-10-30 07:37:05 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2018:3096 https://access.redhat.com/errata/RHSA-2018:3096

Comment 11 errata-xmlrpc 2018-10-30 08:56:32 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

Comment 13 errata-xmlrpc 2019-08-13 14:59:24 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2019:2473 https://access.redhat.com/errata/RHSA-2019:2473