New issue
Advanced search Search tips

Issue 873500 link

Starred by 1 user

Issue metadata

Status: Fixed
Owner:
Closed: Aug 15
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Chrome
Pri: 2
Type: Bug-Security



Sign in to add a comment

CVE-2018-1120 CrOS: Vulnerability reported in Linux kernel

Project Member Reported by vomit.go...@appspot.gserviceaccount.com, Aug 12

Issue description

VOMIT (go/vomit) has received an external vulnerability report for the Linux kernel. 

Advisory: CVE-2018-1120
  Details: http://vomit.googleplex.com/advisory?id=CVE/CVE-2018-1120
  CVSS severity score: 3.5/10.0
  Description:

A flaw was found affecting the Linux kernel before version 4.17. By mmap()ing a FUSE-backed file onto a process's memory containing command line arguments (or environment strings), an attacker can cause utilities from psutils or procps (such as ps, w) or any other program which makes a read() call to the /proc/<pid>/cmdline (or /proc/<pid>/environ) files to block indefinitely (denial of service) or for some controlled time (as a synchronization primitive for other attacks).



This bug was filed by http://go/vomit
Please contact us at vomit-team@google.com if you need any assistance.

 
Cc: groeck@chromium.org wonderfly@google.com
Labels: M-70 Pri-2
Owner: zsm@chromium.org
Status: Assigned (was: Untriaged)
Upstream commit 7f7ccc2ccc2e ("proc: do not access cmdline nor environ from file-backed areas"). Fixed in chromeos-4.14 with merge of v4.14.42. Not fixed in older releases. A comment in the commit log suggests that the fix may be needed in older kernels, and if so that it would require manual packport. A quick check reveals that this is the case at least for chromeos-4.4.
Best action is probably to backport the patch to chromeos-4.4, check it as much as possible, request for it to be included in upstream stable releases, and then pull it from there. The risk associated with backports to even older kernels is probably not worth it.
Cc: mikewu@google.com
Labels: Security_Impact-Stable Security_Severity-Low
DoS is not a security event per our severity guidelines, but synchronization primitive might be useful (that's a long shot though). Hence setting low severity. I expect this to be also OK for lakitu, speak up if you disagree.

Recommendation: Apply the patch where it applies cleanly and ship via regular release cycle.
Status: Fixed (was: Assigned)
As the patch is in 4.14 and the impact is set to low, I'll go ahead and close this bug without any further action. Please feel free to reassign if further action is required on this bug.
#5: sgtm.
Project Member

Comment 7 by sheriffbot@chromium.org, Aug 16

Labels: Restrict-View-SecurityNotify
Project Member

Comment 8 by sheriffbot@chromium.org, Nov 22

Labels: -Restrict-View-SecurityNotify allpublic
This bug has been closed for more than 14 weeks. Removing security view restrictions.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Sign in to add a comment