3.16.7-ckt5 -stable review patch. If anyone has any objections, please let me know.
------------------ From: "J. Bruce Fields" <[email protected]> commit 49a068f82a1d30eb585d7804b05948376be6cf9a upstream. A struct xdr_stream at a page boundary might point to the end of one page or the beginning of the next, but xdr_truncate_encode isn't prepared to handle the former. This can cause corruption of NFSv4 READDIR replies in the case that a readdir entry that would have exceeded the client's dircount/maxcount limit would have ended exactly on a 4k page boundary. You're more likely to hit this case on large directories. Other xdr_truncate_encode callers are probably also affected. Reported-by: Holger Hoffstätte <[email protected]> Tested-by: Holger Hoffstätte <[email protected]> Fixes: 3e19ce762b53 "rpc: xdr_truncate_encode" Signed-off-by: J. Bruce Fields <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- net/sunrpc/xdr.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 23fb4e75e245..25ef792dfee6 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -605,7 +605,7 @@ void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) struct kvec *head = buf->head; struct kvec *tail = buf->tail; int fraglen; - int new, old; + int new; if (len > buf->len) { WARN_ON_ONCE(1); @@ -627,8 +627,8 @@ void xdr_truncate_encode(struct xdr_stream *xdr, size_t len) buf->len -= fraglen; new = buf->page_base + buf->page_len; - old = new + fraglen; - xdr->page_ptr -= (old >> PAGE_SHIFT) - (new >> PAGE_SHIFT); + + xdr->page_ptr = buf->pages + (new >> PAGE_SHIFT); if (buf->page_len && buf->len == len) { xdr->p = page_address(*xdr->page_ptr); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
