Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 23 Apr 2019 09:53:40 +0000
From:      bugzilla-noreply@freebsd.org
To:        net@FreeBSD.org
Subject:   [Bug 233955] [panic] Page fault in in6_purgeaddr (triggered by net/wireguard)
Message-ID:  <bug-233955-7501-4LM28LBwZd@https.bugs.freebsd.org/bugzilla/>
In-Reply-To: <bug-233955-7501@https.bugs.freebsd.org/bugzilla/>
References:  <bug-233955-7501@https.bugs.freebsd.org/bugzilla/>

next in thread | previous in thread | raw e-mail | index | archive | help
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D233955

--- Comment #22 from Jason A. Donenfeld <jason@zx2c4.com> ---
Alright, I've now spent a bit of time tracking down these race conditions a=
nd
reproducing them in a VM. It looks like there are two separate kernel race
conditions:

- SIOCGIFSTATUS races with SIOCIFDESTROY, which was being triggered by the =
call
to ifconfig(8) in the route monitor script. This should be now fixed by:
https://git.zx2c4.com/WireGuard/patch/?id=3D90c546598c0a9d9da82c138c6c9c139=
6c453368e

- The asynchronous callback of IPv6 Link Local DAD conflict with both
SIOCIFDESTROY and the /dev/tun cloning mechanism, resulting in a wide varie=
ty
of crashes with dangling pointers on IPv6 address lists. I'm able to trigger
this by just running `while true; do ifconfig tun0 create; ifconfig tun0
destroy; done` and after a while, there's one sort of crash. This should no=
w be
fixed by:
https://git.zx2c4.com/wireguard-go/patch/?id=3Dbb42ec7d185ab5f5cd3867ac1258=
edff86b7f307

I'd appreciate it if Michael Muenz could test these and make sure it fixes =
his
own reproducer. After, Bernhard Froehlich can backport those two packages i=
nto
the ports tree. Finally, THIS BUG SHOULD REMAIN OPEN until the FreeBSD kern=
el
team actually gets the man power to fix these race conditions; the above on=
ly
represents a few workarounds but does not address the underlying issue of t=
his
bug at all.

--=20
You are receiving this mail because:
You are the assignee for the bug.=



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-233955-7501-4LM28LBwZd>