Messages in this thread | | | Date | Thu, 31 Dec 2015 08:12:53 +0100 | From | Willy Tarreau <> | Subject | Re: [PATCH] unix: properly account for FDs passed over unix sockets |
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On Thu, Dec 31, 2015 at 03:08:53PM +0900, Tetsuo Handa wrote: > Willy Tarreau wrote: > > On Wed, Dec 30, 2015 at 09:58:42AM +0100, Hannes Frederic Sowa wrote: > > > The MSG_PEEK code should not be harmful and the patch is good as is. I > > > first understood from the published private thread, that it is possible > > > for a program to exceed the rlimit of fds. But the DoS is only by > > > keeping the fds in flight and not attaching them to any program. > > > > Exactly. The real issue is when these FDs become very expensive such as > > pipes full of data. > > > > As you wrote how to abuse this vulnerability which exists in Linux 2.0 > and later kernel, I quote a short description from private thread. > > "an unprivileged user consumes all file descriptors so that other > unprivileged user cannot work" and "an unprivileged user consumes all > kernel memory so that the OOM killer kills almost all processes before > the culprit process is killed (CVE-2013-4312)". > > Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Mitigates: CVE-2013-4312 (Linux 2.0+)
Well I didn't reveal any secret as it was publicly reported first in 2010, it's only that Mark sent us the proof of concept exploit on the security list recently :-)
https://bugzilla.kernel.org/show_bug.cgi?id=20402
Anyway I'll resend the patch with your reported-by, the CVE and Hannes' ACK.
Thanks! Willy
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