Bug 726478

Summary: Your system may be seriously compromised! /usr/bin/skype attempted to mmap low kernel memory.
Product: [Fedora] Fedora Reporter: Bibby <lillabibba>
Component: selinux-policyAssignee: Miroslav Grepl <mgrepl>
Status: CLOSED NOTABUG QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: 13CC: dominick.grift, dwalsh, mgrepl
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Whiteboard: setroubleshoot_trace_hash:6850c83aa71bc5ffbe8d474f12de2374991bb374ada5f06b926b59979989f4a1
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2011-07-29 12:07:50 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Bibby 2011-07-28 18:49:41 UTC
Summary:

Your system may be seriously compromised! /usr/bin/skype attempted to mmap low
kernel memory.

Detailed Description:

SELinux has denied the skype the ability to mmap low area of the kernel address
space. The ability to mmap a low area of the address space, as configured by
/proc/sys/kernel/mmap_min_addr. Preventing such mappings helps protect against
exploiting null deref bugs in the kernel. All applications that need this access
should have already had policy written for them. If a compromised application
tries modify the kernel this AVC would be generated. This is a serious issue.
Your system may very well be compromised.

Allowing Access:

Contact your security administrator and report this issue.

Additional Information:

Source Context                unconfined_u:unconfined_r:unconfined_execmem_t:s0-
                              s0:c0.c1023
Target Context                unconfined_u:unconfined_r:unconfined_execmem_t:s0-
                              s0:c0.c1023
Target Objects                None [ memprotect ]
Source                        skype
Source Path                   /usr/bin/skype
Port                          <Unknown>
Host                          (removed)
Source RPM Packages           skype-2.2.0.35-fc10
Target RPM Packages           
Policy RPM                    selinux-policy-3.7.19-10.fc13
Selinux Enabled               True
Policy Type                   targeted
Enforcing Mode                Enforcing
Plugin Name                   mmap_zero
Host Name                     (removed)
Platform                      Linux (removed) 2.6.33.3-85.fc13.i686 #1 SMP Thu May
                              6 18:44:12 UTC 2010 i686 i686
Alert Count                   187
First Seen                    Thu 28 Jul 2011 08:47:21 PM CEST
Last Seen                     Thu 28 Jul 2011 08:47:56 PM CEST
Local ID                      bb39b9be-8910-45aa-a8d9-1f4ad9c41c41
Line Numbers                  

Raw Audit Messages            

node=(removed) type=AVC msg=audit(1311878876.705:2906): avc:  denied  { mmap_zero } for  pid=7866 comm="skype" scontext=unconfined_u:unconfined_r:unconfined_execmem_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_execmem_t:s0-s0:c0.c1023 tclass=memprotect

node=(removed) type=SYSCALL msg=audit(1311878876.705:2906): arch=40000003 syscall=192 per=400000 success=no exit=-13 a0=0 a1=100000 a2=0 a3=4022 items=0 ppid=1 pid=7866 auid=500 uid=500 gid=500 euid=500 suid=500 fsuid=500 egid=500 sgid=500 fsgid=500 tty=(none) ses=1 comm="skype" exe="/usr/bin/skype" subj=unconfined_u:unconfined_r:unconfined_execmem_t:s0-s0:c0.c1023 key=(null)



Hash String generated from  mmap_zero,skype,unconfined_execmem_t,unconfined_execmem_t,memprotect,mmap_zero
audit2allow suggests:

#============= unconfined_execmem_t ==============
#!!!! This avc can be allowed using the boolean 'mmap_low_allowed'

allow unconfined_execmem_t self:memprotect mmap_zero;

Comment 1 Daniel Walsh 2011-07-29 12:07:50 UTC
Alert says it all.

F13 is no longer supported.