#567094 recvmsg(2): please mention that MSG_CTRUNC can be set due to permissions errors

Package:
manpages-dev
Source:
manpages
Submitter:
Török Edwin
Date:
2015-03-12 13:03:05 UTC
Severity:
normal
#567094#5
Date:
2010-01-27 09:26:42 UTC
From:
To:
"man 2 recvmsg" says:
       MSG_CTRUNC
              indicates that some control data were discarded due to lack of space in the buffer for ancillary data.

That doesn't mention that MSG_CTRUNC can be set due to a permission error also.
SELinux can deny file descriptor passing, in which case the receiving
application gets a message with MSG_CTRUNC set and controllen zero!

See here for one example where this happens https://wwws.clamav.net/bugzilla/show_bug.cgi?id=1700#c3
#567094#10
Date:
2010-02-03 05:00:46 UTC
From:
To:
2010/1/27 Török Edwin <edwintorok@gmail.com>:

(Upstream maintainer here...)

I created an account on this bugzilla, but still it tells me:

"You are not authorized to access bug #1700. "

So, I can't read this bug to get more info.

Cheers,

Michael
#567094#15
Date:
2010-02-03 10:34:34 UTC
From:
To:
The relevant part to MSG_CTRUNC starts at comment #3.

There is also a similar issue described here:
http://osdir.com/ml/fedora-selinux/2009-09/msg00071.html

Best regards,
--Edwin