From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net] net: sctp: fix sctp_connectx abi for ia32 emulation/compat mode Date: Tue, 18 Feb 2014 16:07:30 -0500 (EST) Message-ID: <20140218.160730.1363339001953107311.davem@davemloft.net> References: <1392635471-31528-1-git-send-email-dborkman@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org To: dborkman@redhat.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:35893 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751216AbaBRVHc (ORCPT ); Tue, 18 Feb 2014 16:07:32 -0500 In-Reply-To: <1392635471-31528-1-git-send-email-dborkman@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Daniel Borkmann Date: Mon, 17 Feb 2014 12:11:11 +0100 > SCTP's sctp_connectx() abi breaks for 64bit kernels compiled with 32bit > emulation (e.g. ia32 emulation or x86_x32). Due to internal usage of > 'struct sctp_getaddrs_old' which includes a struct sockaddr pointer, > sizeof(param) check will always fail in kernel as the structure in > 64bit kernel space is 4bytes larger than for user binaries compiled > in 32bit mode. Thus, applications making use of sctp_connectx() won't > be able to run under such circumstances. > > Introduce a compat interface in the kernel to deal with such > situations by using a 'struct compat_sctp_getaddrs_old' structure > where user data is copied into it, and then sucessively transformed > into a 'struct sctp_getaddrs_old' structure with the help of > compat_ptr(). That fixes sctp_connectx() abi without any changes > needed in user space, and lets the SCTP test suite pass when compiled > in 32bit and run on 64bit kernels. > > Fixes: f9c67811ebc0 ("sctp: Fix regression introduced by new sctp_connectx api") > Signed-off-by: Daniel Borkmann Applied and queued up for -stable, thanks.