diff options
| author | Frank Sorenson <sorenson@redhat.com> | 2018-10-30 23:10:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-22 09:32:48 +0300 |
| commit | 7b86a9a6c9fe6ae8c810121a2396dc3a652c8b67 (patch) | |
| tree | 74b720ace7c862d7e1308597013d9a340ea7e801 /net/sunrpc | |
| parent | 02948fa1d5f2fc18b899f880255532f4336fbf65 (diff) | |
| download | linux-7b86a9a6c9fe6ae8c810121a2396dc3a652c8b67.tar.xz | |
sunrpc: correct the computation for page_ptr when truncating
commit 5d7a5bcb67c70cbc904057ef52d3fcfeb24420bb upstream.
When truncating the encode buffer, the page_ptr is getting
advanced, causing the next page to be skipped while encoding.
The page is still included in the response, so the response
contains a page of bogus data.
We need to adjust the page_ptr backwards to ensure we encode
the next page into the correct place.
We saw this triggered when concurrent directory modifications caused
nfsd4_encode_direct_fattr() to return nfserr_noent, and the resulting
call to xdr_truncate_encode() corrupted the READDIR reply.
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/xdr.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 2a81e77c4477..6de975ae7f5b 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -638,11 +638,10 @@ void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) /* xdr->iov should already be NULL */ return; } - if (fraglen) { + if (fraglen) xdr->end = head->iov_base + head->iov_len; - xdr->page_ptr--; - } /* (otherwise assume xdr->end is already set) */ + xdr->page_ptr--; head->iov_len = len; buf->len = len; xdr->p = head->iov_base + head->iov_len; |