Bug 964377 - SELinux is preventing chrome from 'mmap_zero' accesses on the memprotect .
SELinux is preventing chrome from 'mmap_zero' accesses on the memprotect .
Status: CLOSED DUPLICATE of bug 882623
Product: Fedora
Classification: Fedora
Component: kernel (Show other bugs)
i686 Unspecified
unspecified Severity unspecified
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Assigned To: Kernel Maintainer List
Fedora Extras Quality Assurance
: Reopened
Depends On:
  Show dependency treegraph
Reported: 2013-05-18 02:48 EDT by Mikhail
Modified: 2013-06-07 11:08 EDT (History)
9 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2013-06-07 11:08:17 EDT
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Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Mikhail 2013-05-18 02:48:04 EDT
Description of problem:
SELinux is preventing chrome from 'mmap_zero' accesses on the memprotect .

*****  Plugin mmap_zero (53.1 confidence) suggests  **************************

If you do not think chrome should need to mmap low memory in the kernel.
Then you may be under attack by a hacker, this is a very dangerous access.
contact your security administrator and report this issue.

*****  Plugin catchall_boolean (42.6 confidence) suggests  *******************

If you want to control the ability to mmap a low area of the address space, as configured by /proc/sys/kernel/mmap_min_addr.
Then you must tell SELinux about this by enabling the 'mmap_low_allowed' boolean.
You can read 'unconfined_selinux' man page for more details.
setsebool -P mmap_low_allowed 1

*****  Plugin catchall (5.76 confidence) suggests  ***************************

If you believe that chrome should be allowed mmap_zero access on the  memprotect by default.
Then you should report this as a bug.
You can generate a local policy module to allow this access.
allow this access for now by executing:
# grep chrome /var/log/audit/audit.log | audit2allow -M mypol
# semodule -i mypol.pp

Additional Information:
Source Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
Target Context                unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1
Target Objects                 [ memprotect ]
Source                        chrome
Source Path                   chrome
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           
Target RPM Packages           
Policy RPM                    selinux-policy-3.12.1-44.fc19.noarch
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Host Name                     (removed)
Platform                      Linux (removed) 3.9.2-301.fc19.i686.PAE #1 SMP Mon
                              May 13 12:47:57 UTC 2013 i686 i686
Alert Count                   670
First Seen                    2013-05-08 09:05:21 YEKT
Last Seen                     2013-05-18 00:18:27 YEKT
Local ID                      6025d625-9545-4077-bdfc-507c9a8b51bc

Raw Audit Messages
type=AVC msg=audit(1368814707.93:491): avc:  denied  { mmap_zero } for  pid=5822 comm="wine-preloader" scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=memprotect

Hash: chrome,unconfined_t,unconfined_t,memprotect,mmap_zero


#============= unconfined_t ==============

#!!!! This avc can be allowed using the boolean 'mmap_low_allowed'
allow unconfined_t self:memprotect mmap_zero;

audit2allow -RYou must regenerate interface info by running /usr/bin/sepolgen-ifgen

Additional info:
reporter:       libreport-2.1.4
hashmarkername: setroubleshoot
kernel:         3.9.2-301.fc19.i686.PAE
type:           libreport

Potential duplicate: bug 870670
Comment 1 Daniel Walsh 2013-05-18 06:21:35 EDT

*** This bug has been marked as a duplicate of bug 870670 ***
Comment 2 Mikhail 2013-06-06 17:29:44 EDT
Why you think that this is bug of Google Chrome???
I see this alert only when open very much tabs ~100!!!
Seems PAE kernel have problem when application try allocate very many memory. Kernel begins  allocate low address and it is trigger this alert. 

Can you check this???
Comment 3 Daniel Walsh 2013-06-07 09:24:31 EDT
Well then it would be a kernel bug.
Comment 4 Eric Paris 2013-06-07 11:08:17 EDT
application is the wine-preloader

*** This bug has been marked as a duplicate of bug 882623 ***

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