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authorBenjamin Coddington <bcodding@redhat.com>2015-11-20 09:55:30 -0500
committerTrond Myklebust <trond.myklebust@primarydata.com>2015-11-23 22:03:15 -0500
commit38b7631fbe42e6e247e9fc9879f961b14a687e3b (patch)
treeedcf8b437182b980a936bc11a46a292c31173c7f /net/sunrpc/backchannel_rqst.c
parentnfs4: start callback_ident at idr 1 (diff)
downloadlinux-dev-38b7631fbe42e6e247e9fc9879f961b14a687e3b.tar.xz
linux-dev-38b7631fbe42e6e247e9fc9879f961b14a687e3b.zip
nfs4: limit callback decoding to received bytes
A truncated cb_compound request will cause the client to decode null or data from a previous callback for nfs4.1 backchannel case, or uninitialized data for the nfs4.0 case. This is because the path through svc_process_common() advances the request's iov_base and decrements iov_len without adjusting the overall xdr_buf's len field. That causes xdr_init_decode() to set up the xdr_stream with an incorrect length in nfs4_callback_compound(). Fixing this for the nfs4.1 backchannel case first requires setting the correct iov_len and page_len based on the length of received data in the same manner as the nfs4.0 case. Then the request's xdr_buf length can be adjusted for both cases based upon the remaining iov_len and page_len. Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'net/sunrpc/backchannel_rqst.c')
-rw-r--r--net/sunrpc/backchannel_rqst.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/net/sunrpc/backchannel_rqst.c b/net/sunrpc/backchannel_rqst.c
index 229956bf8457..95f82d8d4888 100644
--- a/net/sunrpc/backchannel_rqst.c
+++ b/net/sunrpc/backchannel_rqst.c
@@ -353,12 +353,20 @@ void xprt_complete_bc_request(struct rpc_rqst *req, uint32_t copied)
{
struct rpc_xprt *xprt = req->rq_xprt;
struct svc_serv *bc_serv = xprt->bc_serv;
+ struct xdr_buf *rq_rcv_buf = &req->rq_rcv_buf;
spin_lock(&xprt->bc_pa_lock);
list_del(&req->rq_bc_pa_list);
xprt_dec_alloc_count(xprt, 1);
spin_unlock(&xprt->bc_pa_lock);
+ if (copied <= rq_rcv_buf->head[0].iov_len) {
+ rq_rcv_buf->head[0].iov_len = copied;
+ rq_rcv_buf->page_len = 0;
+ } else {
+ rq_rcv_buf->page_len = copied - rq_rcv_buf->head[0].iov_len;
+ }
+
req->rq_private_buf.len = copied;
set_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);