On Wed, Aug 28, 2013 at 7:21 PM, Toralf Förster <toralf.foerster@xxxxxx> wrote: > On 08/27/2013 08:06 PM, J. Bruce Fields wrote: >> On Tue, Aug 13, 2013 at 05:53:14PM -0400, bfields wrote: >>> On Mon, Aug 12, 2013 at 04:36:40PM +0200, Jan Kara wrote: >>>> On Sun 11-08-13 11:48:49, Toralf Förster wrote: >>>>> so that the server either crashes (if it is a user mode linux image) or at least its reboot functionality got broken >>>>> - if the NFS server is hammered with scary NFS calls using a fuzzy tool running at a remote NFS client under a non-privileged user id. >>>>> >>>>> It can re reproduced, if >>>>> - the NFS share is an EXT3 or EXT4 directory >>>>> - and it is created at file located at tempfs and mounted via loop device >>>>> - and the NFS server is forced to umount the NFS share >>>>> - and the server forced to restart the NSF service afterwards >>>>> - and trinity is used >>>>> >>>>> I could find a scenario for an automated bisect. 2 times it brought this commit >>>>> commit 68a3396178e6688ad7367202cdf0af8ed03c8727 >>>>> Author: J. Bruce Fields <bfields@xxxxxxxxxx> >>>>> Date: Thu Mar 21 11:21:50 2013 -0400 >>>>> >>>>> nfsd4: shut down more of delegation earlier >>> >>> Thanks for the report. I think I see the problem--after this commit >>> nfs4_set_delegation() failures result in nfs4_put_delegation being >>> called, but nfs4_put_delegation doesn't free the nfs4_file that has >>> already been set by alloc_init_deleg(). >>> >>> Let me think about how to fix that.... >> >> Sorry for the slow response--can you check whether this fixes the >> problem? >> > Yes. > > With the attached patch the problem can't be reproduced any longer with > the prepared test case and current git kernels. BTW: Is nobody else fuzz testing NFS? Or are these bugs just more likely to hit on UML? This is not the first NFS issue found by Toralf using UML and Trinity. -- Thanks, //richard -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
