2008-01-25 17:02:05

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 038/112] NFS: Use unsigned intermediates for manipulating header lengths (NFSv3 XDR)

From: Chuck Lever <[email protected]>

Clean up: prevent length underflow and mixed sign comparisons when
unmarshalling NFS version 3 read, readdir, and readlink replies.

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

fs/nfs/nfs3xdr.c | 27 +++++++++++++++------------
1 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 616d326..3917e2f 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -506,9 +506,9 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
struct kvec *iov = rcvbuf->head;
struct page **page;
- int hdrlen, recvd;
+ size_t hdrlen;
+ u32 len, recvd, pglen;
int status, nr;
- unsigned int len, pglen;
__be32 *entry, *end, *kaddr;

status = ntohl(*p++);
@@ -527,7 +527,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
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");
@@ -549,7 +549,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
len = ntohl(*p++); /* string length */
p += XDR_QUADLEN(len) + 2; /* name + cookie */
if (len > NFS3_MAXNAMLEN) {
- dprintk("NFS: giant filename in readdir (len %x)!\n",
+ dprintk("NFS: giant filename in readdir (len 0x%x)!\n",
len);
goto err_unmap;
}
@@ -570,7 +570,7 @@ nfs3_xdr_readdirres(struct rpc_rqst *req, __be32 *p, struct nfs3_readdirres *res
len = ntohl(*p++);
if (len > NFS3_FHSIZE) {
dprintk("NFS: giant filehandle in "
- "readdir (len %x)!\n", len);
+ "readdir (len 0x%x)!\n", len);
goto err_unmap;
}
p += XDR_QUADLEN(len);
@@ -815,7 +815,8 @@ nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
{
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;

@@ -827,7 +828,7 @@ nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)

/* 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;
}
@@ -835,7 +836,7 @@ nfs3_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
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. "
@@ -863,7 +864,9 @@ static int
nfs3_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
{
struct kvec *iov = req->rq_rcv_buf.head;
- int status, count, ocount, recvd, hdrlen;
+ size_t hdrlen;
+ u32 count, ocount, recvd;
+ int status;

status = ntohl(*p++);
p = xdr_decode_post_op_attr(p, res->fattr);
@@ -871,7 +874,7 @@ nfs3_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
if (status != 0)
return -nfs_stat_to_errno(status);

- /* Decode reply could and EOF flag. NFSv3 is somewhat redundant
+ /* Decode reply count and EOF flag. NFSv3 is somewhat redundant
* in that it puts the count both in the res struct and in the
* opaque data count. */
count = ntohl(*p++);
@@ -886,7 +889,7 @@ nfs3_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");
@@ -896,7 +899,7 @@ nfs3_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;
res->eof = 0;
}