I would call his bug, a bug and a denial of service that any user could trigger. Thanks, LDB Mike Siedelberg wrote:

I thought this list was for SECURITY issues, which is why I subscribed to it. Aren't there any other lists for discussing normal system bugs that this sort of traffic should go to?

I find a lot of unnecessary chatter on non-security issues. I really hate to censor anything, but on these lists that aren't moderated (presuming that it's not monitored) sometimes discussions get carried away.

Just thought I would raise the point.

Mike Siedelberg Jackson National Life Insurance-IT Security Desk Phone 517-367-3546 Cell Phone 517-230-0922

Marco Munderloh 07/25/2006 12:31 PM

To suse-security@suse.com cc

Subject [suse-security] Bug in nfsd from kernel 2.6.16.21-0.13

Hello,

I discovered a bug in the nfs daemon delivered with the kernel update to kernel 2.6.16.21-0.13.

When accessing a large amount of files over an nfs export from a machine with SuSE 10.1 and kernel 2.6.16.21-0.13, stale NFS handles occur. After a short period (3-5s) the files are accessible again. "grep -R hello" * triggers the bug for example.

My configuration: SuSE 10.1 with kernel 2.6.16.21-0.13, NFS export of an XFS filesystem mounted on different clients with autofs (UDP and TCP).

Degrading back the kernel to 2.6.16.13-4 and all works fine again.

Regards, Marco

Mike Siedelberg schrieb: Hi Mike,

I thought this list was for SECURITY issues

Marco did indeed describe a security relevant regression. Actuallly it is a netowrk exploitable(*) denial of service attack issue.

When accessing a large amount of files over an nfs export from a machine with SuSE 10.1 and kernel 2.6.16.21-0.13, stale NFS handles occur.

Regards, --martin

I opened a bug for this now, but you could have done yourself. I have cced Marco in the report. I already did that myself: https://bugzilla.novell.com/show_bug.cgi?id=195040

The bug seems to occur in SLES9 before. Adding "no_subtree_check" to the export options in /etc/exports works as a workaround. Nevertheless I don't think it's a good idea that a novell account is needed to post a bug in Bugzilla. Giving there full address surely scares some good people off. Regards, Marco