From: Dan Carpenter <dan.carpenter@oracle.com>
To: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>,
"David S. Miller" <davem@davemloft.net>,
linux-nfs@vger.kernel.org, netdev@vger.kernel.org,
kernel-janitors@vger.kernel.org
Subject: [patch -stable] svcrdma: underflow issue in decode_write_list()
Date: Fri, 12 Jul 2013 06:39:03 +0000 [thread overview]
Message-ID: <20130712063903.GB29320@longonot.mountain> (raw)
My static checker marks everything from ntohl() as untrusted and it
complains we could have an underflow problem doing:
return (u32 *)&ary->wc_array[nchunks];
Also on 32 bit systems the upper bound check could overflow.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c
index 8d2eddd..65b1462 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_marshal.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c
@@ -98,6 +98,7 @@ void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch,
*/
static u32 *decode_write_list(u32 *va, u32 *vaend)
{
+ unsigned long start, end;
int nchunks;
struct rpcrdma_write_array *ary @@ -113,9 +114,12 @@ static u32 *decode_write_list(u32 *va, u32 *vaend)
return NULL;
}
nchunks = ntohl(ary->wc_nchunks);
- if (((unsigned long)&ary->wc_array[0] +
- (sizeof(struct rpcrdma_write_chunk) * nchunks)) >
- (unsigned long)vaend) {
+
+ start = (unsigned long)&ary->wc_array[0];
+ end = (unsigned long)vaend;
+ if (nchunks < 0 ||
+ nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
+ (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
ary, nchunks, vaend);
return NULL;
@@ -129,6 +133,7 @@ static u32 *decode_write_list(u32 *va, u32 *vaend)
static u32 *decode_reply_array(u32 *va, u32 *vaend)
{
+ unsigned long start, end;
int nchunks;
struct rpcrdma_write_array *ary (struct rpcrdma_write_array *)va;
@@ -143,9 +148,12 @@ static u32 *decode_reply_array(u32 *va, u32 *vaend)
return NULL;
}
nchunks = ntohl(ary->wc_nchunks);
- if (((unsigned long)&ary->wc_array[0] +
- (sizeof(struct rpcrdma_write_chunk) * nchunks)) >
- (unsigned long)vaend) {
+
+ start = (unsigned long)&ary->wc_array[0];
+ end = (unsigned long)vaend;
+ if (nchunks < 0 ||
+ nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
+ (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
ary, nchunks, vaend);
return NULL;
next reply other threads:[~2013-07-12 6:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-12 6:39 Dan Carpenter [this message]
2013-07-12 8:24 ` [patch -stable] svcrdma: underflow issue in decode_write_list() walter harms
2013-07-12 20:26 ` J. Bruce Fields
2013-07-14 19:40 ` Dan Carpenter
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