On 01/29/2013 11:20 AM, William Roberts wrote:
I see I misread domain.te, only urandom is allowed by domain. Isn't
random world readable though, won't we run into a compatibility issue
with those that need it? Perhaps adding this into a boolean is the
right way to go. People shouldn't have to re-write their seapp
contexts to get apps to work.
Fair enough, feel free to add it. Not sure it justifies a boolean however.
On Mon, Jan 28, 2013 at 2:57 PM, William Roberts
<[email protected]> wrote:
random and urandom are allowed by domain, this is an MLS issue.
Try applying this patch:
diff --git a/device.te b/device.te
index 7818ce8..72c3e54 100644
--- a/device.te
+++ b/device.te
@@ -29,11 +29,11 @@ type ptmx_device, dev_type, mlstrustedobject;
type qemu_device, dev_type;
type kmsg_device, dev_type;
type null_device, dev_type, mlstrustedobject;
-type random_device, dev_type;
+type random_device, dev_type, mlstrustedobject;
type serial_device, dev_type;
type socket_device, dev_type;
type tty_device, dev_type;
-type urandom_device, dev_type;
+type urandom_device, dev_type, mlstrustedobject;
type video_device, dev_type;
type vcs_device, dev_type;
type zero_device, dev_type;
On Mon, Jan 28, 2013 at 2:30 PM, Peck, Michael A <[email protected]> wrote:
A crypto (secure voice) app I am testing fails to start – it is trying to
read /dev/random:
<5>[ 2951.029571] type=1400 audit(1359410942.187:32): avc: denied { read }
for
pid=2435 comm=4173796E635461736B202331 name="random" dev=tmpfs ino=4012
scontext=u:r:untrusted_app:s0:c50,c256 tcontext=u:object_r:random_device:s0
tclass=chr_file
Would it be reasonable to add a “allow domain random_device:chr_file
r_file_perms;” rule to allow all apps to read /dev/random?
I think the main threat is that a malicious app could potentially keep
reading from /dev/random and use up the entropy pool (preventing others from
reading /dev/random).
Some might say the app should use /dev/urandom instead. At which time
others would probably then complain that /dev/urandom is “not good enough”.
Not sure that I personally want to take sides on /dev/random vs.
/dev/urandom. J
--
Michael Peck
The MITRE Corporation
--
Respectfully,
William C Roberts
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