Bug 210012

Summary:	fc6- kernel allows stracing of kernel threads
Product:	[Fedora] Fedora	Reporter:	Arjan van de Ven <arjan>
Component:	kernel	Assignee:	Dave Jones <davej>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Brian Brock <bbrock>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	davej, mjc, pfrields, roland, wtogami
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	kernel-2.6.18-1.2753.fc6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2006-10-31 04:54:29 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:

Description Arjan van de Ven 2006-10-09 15:03:34 UTC

Description of problem:

strace -p <pid of a kernel thread>

does not give permission denied!

Comment 1 Arjan van de Ven 2006-10-09 16:26:43 UTC

(strace is a security sensitive operation, someone needs to evaluate how serious
this is)

Comment 2 Roland McGrath 2006-10-10 04:19:55 UTC

This is a simple check accidentally omitted when converting the ptrace entry
checks for the new utrace-based code.  It only affects the kthread case (tasks
with no ->mm), and the uid and LSM checks are still performed so this can only
be done by root (and perhaps can't be done under selinux policy, don't know).
I don't think it rises to the level of a security concern.

I have a fix on its way.

Comment 3 Roland McGrath 2006-10-10 04:24:01 UTC

I committed the fixed utrace patch to kernel/devel, it will be in davej's next
kernel build.  I only wish this were a more interesting and auspicious bug to go
with the palindromic bug number.

Comment 4 Roland McGrath 2006-10-31 04:54:29 UTC

This was fixed in the FC-6 release kernel.