[61/88] nfsd4: fix decoding of compounds across page boundaries

Steven Rostedt
2013-08-13T16:29:48Z

[-- Attachment #1: 0061-nfsd4-fix-decoding-of-compounds-across-page-boundari.patch --]
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3.6.11.7-rc1 stable review patch.
If anyone has any objections, please let me know.

------------------

From: "J. Bruce Fields" <bfields@redhat.com>

[ Upstream commit 247500820ebd02ad87525db5d9b199e5b66f6636 ]

A freebsd NFSv4.0 client was getting rare IO errors expanding a tarball.
A network trace showed the server returning BAD_XDR on the final getattr
of a getattr+write+getattr compound. The final getattr started on a
page boundary.

I believe the Linux client ignores errors on the post-write getattr, and
that that's why we haven't seen this before.

Cc: stable@vger.kernel.org
Reported-by: Rick Macklem <rmacklem@uoguelph.ca>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
fs/nfsd/nfs4xdr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 348937b..1f43627 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -161,8 +161,8 @@ static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
*/
memcpy(p, argp->p, avail);
/* step to next page */
- argp->p = page_address(argp->pagelist[0]);
argp->pagelist++;
+ argp->p = page_address(argp->pagelist[0]);
if (argp->pagelen < PAGE_SIZE) {
argp->end = argp->p + (argp->pagelen>>2);
argp->pagelen = 0;
--
1.7.10.4