The following reply was made to PR kern/132734; it has been noted by GNATS.
From: Robert Watson <rwat...@freebsd.org> To: Mikolaj Golub <to.my.troc...@gmail.com> Cc: Alexey Illarionov <littlesav...@orionet.ru>, bug-follo...@freebsd.org Subject: Re: kern/132734: panic in net/if_mib.c Date: Thu, 23 Apr 2009 20:33:43 +0100 (BST) On Thu, 23 Apr 2009, Mikolaj Golub wrote: > SVN rev 191435 on 2009-04-23 18:23:08Z by rwatson > > Merge r191434 from stable/7 to releng/7.2: > > In sysctl_ifdata(), query the ifnet pointer using the index only > once, rather than querying it, validating it, and then re-querying > it without validating it. This may avoid a NULL pointer > dereference and resulting kernel page fault if an interface is > being deleted while bsnmp or other tools are querying data on the > interface. > > The full fix, to properly refcount the interface for the duration > of the sysctl, is in 8.x, but is considered too high-risk for > 7.2, so instead will appear in 7.3 (if all goes well). > > So, Alexey, can you try upgrading to the latest stable/7 or releng/7.2 or > apply attached patch to see if this tweak at least eliminates the instant > panic? I'll try to get the refcount fix into 7-STABLE in about two weeks, assuming no hitches in the 8.x version. This will close a number of related race conditions, which we've had occasional reports of (and others that we haven't). Robert N M Watson Computer Laboratory University of Cambridge _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
