[fedora-india] Fwd: SELinux is preventing /usr/bin/skype from mmap_zero access on the memprotect Unknown.

Tue Aug 9 12:39:00 UTC 2011

Thanks Lakshmi, I would give a try and update you at the earliest.

On Tue, Aug 9, 2011 at 4:26 PM, Lakshmipathi.G <lakshmipathi.g at gmail.com>wrote:

> Hi -
> If you don't have confidential data on your machine, I would suggest you to
> turn of SELinux using "setenforce 0" (it needs root access)
> and then verify it using "getenforce" .  Or disable it completely by
> modifying the file /etc/selinux/config. This is very much easier way.
>
> If you want to use SELinux with Skype,then do -
> 1.add  a selinux policy module  using  audit2allow command - "cat
> /var/log/audit/audit.log  | audit2allow > skype.pp"
>
> 2.Make sure selinux-policy-devel package is installed and now compile the
> module.
> #make -f /usr/share/selinux/devel/Makefile skype.pp
>
> 3)load the module "semodule -i skype.pp "
>
> 4)verify it  - semodule -l | grep skype
>
>
> Sometime back while working on OSS project, I found out SELinux documents
> are extremely rare to find.
> Few of them are -
> Dan Walsh's blog -  http://danwalsh.livejournal.com/
> and Dominick's http://selinux-mac.blogspot.com/
>
> HTH
>
> On Tue, Aug 9, 2011 at 5:23 PM, anjaz ahmed <anjazahmed at gmail.com> wrote:
>
>> Dear friends,
>>
>> Recently upgraded to Fedora 15, the skype application gets crashed
>> frequently.....The error details are as mentioned below. Would be great if
>> someone get it fixed.
>>
>> Thanks
>>
>> =====================================================================
>>
>> SELinux is preventing /usr/bin/skype from mmap_zero access on the
>> memprotect Unknown.
>>
>> ***** Plugin mmap_zero (53.1 confidence) suggests
>> **************************
>>
>> If you do not think /usr/bin/skype should need to mmap low memory in the
>> kernel.
>> Then you may be under attack by a hacker, this is a very dangerous access.
>>
>> Do
>> 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.
>> Do
>> setsebool -P mmap_low_allowed 1
>>
>> ***** Plugin catchall (5.76 confidence) suggests
>> ***************************
>>
>> If you believe that skype should be allowed mmap_zero access on the
>> Unknown memprotect by default.
>> Then you should report this as a bug.
>> You can generate a local policy module to allow this access.
>> Do
>> allow this access for now by executing:
>> # grep threaded-ml /var/log/audit/audit.log | audit2allow -M mypol
>> # semodule -i mypol.pp
>>
>> 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 Unknown [ memprotect ]
>> Source threaded-ml
>> Source Path /usr/bin/skype
>> Port <Unknown>
>> Host anjaz.intelvision.sc
>> Source RPM Packages skype-2.2.0.35-fc10
>> Target RPM Packages
>> Policy RPM selinux-policy-3.9.16-35.fc15
>> Selinux Enabled True
>> Policy Type targeted
>> Enforcing Mode Enforcing
>> Host Name anjaz.intelvision.sc
>> Platform Linux anjaz.intelvision.sc 2.6.38.8-35.fc15.x86_64
>> #1 SMP Wed Jul 6 13:58:54 UTC 2011 x86_64 x86_64
>> Alert Count 125
>> First Seen Tue 09 Aug 2011 03:49:24 PM SCT
>> Last Seen Tue 09 Aug 2011 03:49:27 PM SCT
>> Local ID 943f7e9f-e074-437d-9ad1-cf76ac9f7615
>>
>> Raw Audit Messages
>> type=AVC msg=audit(1312890567.697:245): avc: denied { mmap_zero } for
>> pid=4405 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
>>
>>
>> type=SYSCALL msg=audit(1312890567.697:245): arch=i386 syscall=lgetxattr
>> per=400000 success=no exit=EACCES a0=0 a1=1000 a2=3 a3=22 items=0 ppid=1769
>> pid=4405 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:
>> threaded-ml,unconfined_execmem_t,unconfined_execmem_t,memprotect,mmap_zero
>>
>> audit2allow
>>
>> #============= unconfined_execmem_t ==============
>> #!!!! This avc can be allowed using the boolean 'mmap_low_allowed'
>>
>> allow unconfined_execmem_t self:memprotect mmap_zero;
>>
>> audit2allow -R
>>
>> #============= unconfined_execmem_t ==============
>> #!!!! This avc can be allowed using the boolean 'mmap_low_allowed'
>>
>> allow unconfined_execmem_t self:memprotect mmap_zero;
>>
>>
>>
>> _______________________________________________
>> india mailing list
>> india at lists.fedoraproject.org
>> https://admin.fedoraproject.org/mailman/listinfo/india
>>
>
>
>
> --
> ----
> Cheers,
> Lakshmipathi.G
> FOSS Programmer.
> www.giis.co.in
>
> _______________________________________________
> india mailing list
> india at lists.fedoraproject.org
> https://admin.fedoraproject.org/mailman/listinfo/india
>

-- 
Regards,
Anjaz Ahmed.
Indian Mobile : +91-9597921153
VoIP : +248-2716918
Email : anjazahmed at gmail.com
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