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| author | Frank Sorenson <sorenson@redhat.com> | 2018-10-30 15:10:40 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-21 09:19:23 +0100 |
| commit | 03c91663c0935fd1c7df5539ff6df65db8f57278 (patch) | |
| tree | 3ee6c8e30e9fe6d07f1bfd525015e6a958d2d287 /net | |
| parent | 401182ae096bfb16693bcfb8fcab1bc128a5c6bc (diff) | |
| download | linux-stable-03c91663c0935fd1c7df5539ff6df65db8f57278.tar.gz linux-stable-03c91663c0935fd1c7df5539ff6df65db8f57278.tar.bz2 linux-stable-03c91663c0935fd1c7df5539ff6df65db8f57278.zip | |
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')
| -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 30afbd236656..b53cc0960b5d 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -639,11 +639,10 @@ void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) WARN_ON_ONCE(xdr->iov); 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; |