2008-01-25 17:00:21

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 037/112] NFS: Use unsigned intermediates for manipulating header lengths (NFSv2 XDR)

From: Chuck Lever <[email protected]>

Clean up: prevent length underflow and mixed sign comparisons when
unmarshalling NFS version 2 read, readdir, and readlink replies.

Signed-off-by: Chuck Lever <[email protected]>
Signed-off-by: Trond Myklebust <[email protected]>
---

fs/nfs/nfs2xdr.c | 24 ++++++++++++++----------
1 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 668ab96..1f7ea67 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -262,7 +262,9 @@ static int
nfs_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
{
struct kvec *iov = req->rq_rcv_buf.head;
- int status, count, recvd, hdrlen;
+ size_t hdrlen;
+ u32 count, recvd;
+ int status;

if ((status = ntohl(*p++)))
return -nfs_stat_to_errno(status);
@@ -273,7 +275,7 @@ nfs_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
hdrlen = (u8 *) p - (u8 *) iov->iov_base;
if (iov->iov_len < hdrlen) {
dprintk("NFS: READ reply header overflowed:"
- "length %d > %Zu\n", hdrlen, iov->iov_len);
+ "length %Zu > %Zu\n", hdrlen, iov->iov_len);
return -errno_NFSERR_IO;
} else if (iov->iov_len != hdrlen) {
dprintk("NFS: READ header is short. iovec will be shifted.\n");
@@ -283,11 +285,11 @@ nfs_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
recvd = req->rq_rcv_buf.len - hdrlen;
if (count > recvd) {
dprintk("NFS: server cheating in read reply: "
- "count %d > recvd %d\n", count, recvd);
+ "count %u > recvd %u\n", count, recvd);
count = recvd;
}

- dprintk("RPC: readres OK count %d\n", count);
+ dprintk("RPC: readres OK count %u\n", count);
if (count < res->count)
res->count = count;

@@ -423,9 +425,10 @@ nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
struct kvec *iov = rcvbuf->head;
struct page **page;
- int hdrlen, recvd;
+ size_t hdrlen;
+ unsigned int pglen, recvd;
+ u32 len;
int status, nr;
- unsigned int len, pglen;
__be32 *end, *entry, *kaddr;

if ((status = ntohl(*p++)))
@@ -434,7 +437,7 @@ nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
hdrlen = (u8 *) p - (u8 *) iov->iov_base;
if (iov->iov_len < hdrlen) {
dprintk("NFS: READDIR reply header overflowed:"
- "length %d > %Zu\n", hdrlen, iov->iov_len);
+ "length %Zu > %Zu\n", hdrlen, iov->iov_len);
return -errno_NFSERR_IO;
} else if (iov->iov_len != hdrlen) {
dprintk("NFS: READDIR header is short. iovec will be shifted.\n");
@@ -576,7 +579,8 @@ nfs_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, void *dummy)
{
struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
struct kvec *iov = rcvbuf->head;
- int hdrlen, len, recvd;
+ size_t hdrlen;
+ u32 len, recvd;
char *kaddr;
int status;

@@ -584,14 +588,14 @@ nfs_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, void *dummy)
return -nfs_stat_to_errno(status);
/* Convert length of symlink */
len = ntohl(*p++);
- if (len >= rcvbuf->page_len || len <= 0) {
+ if (len >= rcvbuf->page_len) {
dprintk("nfs: server returned giant symlink!\n");
return -ENAMETOOLONG;
}
hdrlen = (u8 *) p - (u8 *) iov->iov_base;
if (iov->iov_len < hdrlen) {
dprintk("NFS: READLINK reply header overflowed:"
- "length %d > %Zu\n", hdrlen, iov->iov_len);
+ "length %Zu > %Zu\n", hdrlen, iov->iov_len);
return -errno_NFSERR_IO;
} else if (iov->iov_len != hdrlen) {
dprintk("NFS: READLINK header is short. iovec will be shifted.\n");