linux-kernel - Re: [PATCH] fix race in AF

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20070618104059.GY521@postel.suug.ch>
Date:	Mon, 18 Jun 2007 12:40:59 +0200
From:	Thomas Graf <tgraf@...g.ch>
To:	Miklos Szeredi <miklos@...redi.hu>
Cc:	davem@...emloft.net, akpm@...ux-foundation.org,
	viro@....linux.org.uk, alan@...rguk.ukuu.org.uk,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] fix race in AF_UNIX

* Thomas Graf <tgraf@...g.ch> 2007-06-18 12:32
> * Miklos Szeredi <miklos@...redi.hu> 2007-06-18 11:44
> > Garbage collection only ever happens, if the app is sending AF_UNIX
> > sockets over AF_UNIX sockets.  Which is a rather rare case.  And which
> > is basically why this bug went unnoticed for so long.
> > 
> > So my second patch only affects the performance of _exactly_ those
> > apps which might well be bitten by the bug itself.
> 
> That's not entirely the truth. It affects all applications using
> AF_UNIX sockets while file descriptors are being transfered. I
> agree that the performance impact is not severe on most systems
> but if file descriptors are being transfered continously by just
> a single application it can become rather severe.

Also think of the scenario where an application, deliberately or not,
begins a file descriptor tranfser using sendmsg() and the receiving
part never invokes recvmsg() to decrement the inflight counters
again. Every unix socket that gets closed would result in a gc call
locking all sockets.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/