On Mon, Jan 23, 2017 at 11:58:33AM -0500, J. Bruce Fields wrote: > On Sun, Jan 22, 2017 at 05:54:19PM +0100, Christoph Hellwig wrote: > > I've got a report that there NFS clients that send SETATTR requests that > > mix size changes with uid/gid changes > > That sounds a little weird. Do you know anything about which clients, > or how common the behavior is? I've only gotten the bug report and don't know the details. But from my cursory knowledge of NFS spec I suspects it's a loosely coupled flexfiles server that uses uid/gids for access control on the data file. > > (see the recent pynfs patch for an > > artifical reproducer). At least XFS and GFS2 are very unhappy with this, > > and other file systems also don't seem to handle the case correctly. > > Does this cause a crash or corruption, or "just" fail to set the > attributes correctly? (Just wondering how urgent the fix is....). With a XFS debug build it crashes, otherwise it "only" fails to set the attributes. But given that the attributes that fail to be set are owner/group (uid,gid) it would totally break the security model, so I think it's pretty serious. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
