malhuda/msm-4.14
1
0
Fork 0
mirror of https://github.com/rd-stuffs/msm-4.14.git synced 2025-02-20 11:45:48 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

sunrpc: correct the computation for page_ptr when truncating

Browse Source 
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>
This commit is contained in:
Frank Sorenson 2018-10-30 15:10:40 -05:00 committed by Greg Kroah-Hartman
parent dedde93bd6
commit a56609f725
1 changed files with 2 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
net/sunrpc/xdr.c
View File

@ -639,11 +639,10 @@ void xdr_truncate_encode(struct xdr_stream *xdr, size_t len)
WARN_ON_ONCE(xdr->iov); WARN_ON_ONCE(xdr->iov);
return; return;
} }
if (fraglen) { if (fraglen)
xdr->end = head->iov_base + head->iov_len; xdr->end = head->iov_base + head->iov_len;
xdr->page_ptr--;
}
/* (otherwise assume xdr->end is already set) */ /* (otherwise assume xdr->end is already set) */
xdr->page_ptr--;
head->iov_len = len; head->iov_len = len;
buf->len = len; buf->len = len;
xdr->p = head->iov_base + head->iov_len; xdr->p = head->iov_base + head->iov_len;