Messages in this thread | | | From | Piotr Sawicki <> | Subject | Re: [PATCH v1 20/22] Move common usercopy into security_getpeersec_stream | Date | Fri, 3 Aug 2018 11:10:09 +0200 |
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On 07/16/2018 08:24 PM, Casey Schaufler wrote: > [PATCH 20/22] Move common usercopy into security_getpeersec_stream > > The modules implementing hook for getpeersec_stream > don't need to be duplicating the copy-to-user checks. > Moving the user copy part into the infrastructure makes > the security module code simpler and reduces the places > where user copy code may go awry.
Hi,
This change will break the API. Some clients may call getsockopt(..,SO_PEERSEC,..) twice. Firstly, to fetch the length. In that case xxx_socket_getpeersec_stream should return -ERANGE and set *optlen. Secondly, to retrieve a proper security label.
Please take a look at the implementation of the getClientSmackLabel() function in Cynara: https://review.tizen.org/gerrit/#/c/26888/6/src/helpers/creds-socket/creds-socket-inner.cpp Also there is an email thread about this socket option which tells us why it is made this way: "[RFC] SO_PEERSEC - security credentials for Unix stream sockets"
http://lists.jammed.com/linux-security-module/2003/12/0029.html
Regards, Piotr
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