Date: Sat, 20 Aug 2005 18:10:43 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Andrew Thompson <thompsa@freebsd.org> Cc: freebsd-current@freebsd.org, rwatson@FreeBSD.org Subject: Re: [PANIC] 6.0BETA2 in l2ping flood Message-ID: <20050820161042.GA749@garage.freebsd.pl> In-Reply-To: <20050819011734.GA4206@heff.fud.org.nz> References: <b0ba593005081703416d19fbf4@mail.gmail.com> <20050817231838.GA97927@heff.fud.org.nz> <20050818210128.GD18375@garage.freebsd.pl> <20050819011734.GA4206@heff.fud.org.nz>
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--IJpNTDwzlM2Ie8A6 Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 19, 2005 at 01:17:34PM +1200, Andrew Thompson wrote: +> On Thu, Aug 18, 2005 at 11:01:29PM +0200, Pawel Jakub Dawidek wrote: +> > On Thu, Aug 18, 2005 at 11:18:38AM +1200, Andrew Thompson wrote: +> > +> Interesting... I can get exactly the same panic by doing +> > +>=20 +> > +> ifconfig bridge0 create +> > +> <'tcpdump -i bridge0' on another terminal> +> > +> ifconfig bridge0 up +> > +> ifconfig bridge0 destroy +> >=20 +> > Here, when you destroy bridge0, callout handle is also destroyed, +> > but on detach, bpf wants to turn off promiscuous mode and call +> > bridge_init(), because it doesn't have IFF_DRV_RUNNING flag set. +> >=20 +> > bridge_init() calls callout_reset() on destroyed callout handle. +> >=20 +>=20 +> Thanks for explaining this, you have saved me a lot of suffering. +>=20 +> This patch fixes the panic on destroy, is it the correct way to solve +> the problem? I need to commit something before 6.0. My explanation wasn't quite right. callout_reset() is called on a valid handle, but right after that, softc structure if freed, so when softclock calls your function, softc is already dead. Here is a patch which fix it: http://people.freebsd.org/~pjd/patches/if_bridge.c.patch If you don't want to change bridge_softc structure size, you can also verify in bridge_init() if the given 'sc' is on bridge_list list. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --IJpNTDwzlM2Ie8A6 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFDB1YCForvXbEpPzQRAsQBAJ0cRNlI61i1eXMpAO600MPiJ4bragCgn9fA 5rdeujjOGPZvO9Jh3FGdDJs= =LxDD -----END PGP SIGNATURE----- --IJpNTDwzlM2Ie8A6--
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