From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 3.12 32/64] unix: properly account for FDs passed over unix sockets To: Jiri Slaby , Willy Tarreau References: <9065c7d8c8be841107dcd6711ab3779553c68fd7.1455198893.git.jslaby@suse.cz> <20160211173233.GA27734@1wt.eu> <56BD906B.9020904@suse.cz> Cc: stable@vger.kernel.org, linux-kernel@vger.kernel.org, "David S . Miller" , Hannes Frederic Sowa From: Philipp Hahn Message-ID: <56BD9BA2.2060706@pmhahn.de> Date: Fri, 12 Feb 2016 09:45:22 +0100 MIME-Version: 1.0 In-Reply-To: <56BD906B.9020904@suse.cz> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: Am 12.02.2016 um 08:57 schrieb Jiri Slaby: > On 02/11/2016, 06:32 PM, Willy Tarreau wrote: >> On Thu, Feb 11, 2016 at 02:59:08PM +0100, Jiri Slaby wrote: >>> From: willy tarreau >>> >>> 3.12-stable review patch. If anyone has any objections, please let me know. >>> >>> =============== >>> >>> [ Upstream commit 712f4aad406bb1ed67f3f98d04c044191f0ff593 ] >>> >>> It is possible for a process to allocate and accumulate far more FDs than >>> the process' limit by sending them over a unix socket then closing them >>> to keep the process' fd count low. >>> >>> This change addresses this problem by keeping track of the number of FDs >>> in flight per user and preventing non-privileged processes from having >>> more FDs in flight than their configured FD limit. >>> >>> Reported-by: socketpair@gmail.com >>> Reported-by: Tetsuo Handa >>> Mitigates: CVE-2013-4312 (Linux 2.0+) >>> Suggested-by: Linus Torvalds >>> Acked-by: Hannes Frederic Sowa >>> Signed-off-by: Willy Tarreau >>> Signed-off-by: David S. Miller >>> Signed-off-by: Jiri Slaby >> >> A possible issue was reported regarding this patch, and Hannes >> implemented a fix that's not yet in mainline. I guess it's >> preferable to postpone this patch for now. > > yes definitely. Thanks for noting. Yes and no: the above mentioned patch looks innocent now after more bisecting, but there is as a folow-up to the FD-accounting. > For reference: > http://article.gmane.org/gmane.linux.kernel/2142236 Better read the full thread: ; the suspected bad patch is unix: avoid use-after-free in ep_remove_wait_queue Philipp