> On Sep 11, 2019, at 1:40 PM, Benjamin Coddington <bcodding@xxxxxxxxxx> wrote: > > On 11 Sep 2019, at 13:29, Chuck Lever wrote: > >>> On Sep 11, 2019, at 1:26 PM, Benjamin Coddington <bcodding@xxxxxxxxxx> wrote: >>> >>> >>> On 11 Sep 2019, at 12:39, Chuck Lever wrote: >>> >>>>> On Sep 11, 2019, at 12:25 PM, Benjamin Coddington <bcodding@xxxxxxxxxx> wrote: >>>>> >>> >>>>> Instead, I think we want to make sure the mic falls squarely into the tail >>>>> every time. >>>> >>>> I'm not clear how you could do that. The length of the page data is not >>>> known to the client before it parses the reply. Are you suggesting that >>>> gss_unwrap should do it somehow? >>> >>> Is it too niave to always put the mic at the end of the tail? >> >> The size of the page content is variable. >> >> The only way the MIC will fall into the tail is if the page content is >> exactly the largest expected size. When the page content is smaller than >> that, the receive logic will place part or all of the MIC in ->pages. > > Ok, right. But what I meant is that xdr_buf_read_netobj() should be renamed > and repurposed to be "move the mic from wherever it is to the end of > xdr_buf's tail". > > But now I see what you mean, and I also see that it is already trying to do > that.. and we don't want to overlap the copy.. > > So, really, we need the tail to be larger than twice the mic.. less 1. That > means the fix is probably just increasing rslack for krb5i. What's the justification for that particular maximum size? Are you sure the page contents are not spilling into the tail? -- Chuck Lever
