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authorChuck Lever <chuck.lever@oracle.com>2015-02-12 10:14:51 -0500
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2015-02-23 16:54:04 -0500
commit9b1dcbc8cf4679ecf090b343ac31bda6e55ddabe (patch)
treea79e05a22da80e9ffb0318e215a4fdccb0a7493c /net
parentb625a61698619c7af652de2701a2fb17c5c5d66e (diff)
downloadlinux-9b1dcbc8cf4679ecf090b343ac31bda6e55ddabe.tar.bz2
xprtrdma: Store RDMA credits in unsigned variables
Dan Carpenter's static checker pointed out: net/sunrpc/xprtrdma/rpc_rdma.c:879 rpcrdma_reply_handler() warn: can 'credits' be negative? "credits" is defined as an int. The credits value comes from the server as a 32-bit unsigned integer. A malicious or broken server can plant a large unsigned integer in that field which would result in an underflow in the following logic, potentially triggering a deadlock of the mount point by blocking the client from issuing more RPC requests. net/sunrpc/xprtrdma/rpc_rdma.c: 876 credits = be32_to_cpu(headerp->rm_credit); 877 if (credits == 0) 878 credits = 1; /* don't deadlock */ 879 else if (credits > r_xprt->rx_buf.rb_max_requests) 880 credits = r_xprt->rx_buf.rb_max_requests; 881 882 cwnd = xprt->cwnd; 883 xprt->cwnd = credits << RPC_CWNDSHIFT; 884 if (xprt->cwnd > cwnd) 885 xprt_release_rqst_cong(rqst->rq_task); Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: eba8ff660b2d ("xprtrdma: Move credit update to RPC . . .") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net')
-rw-r--r--net/sunrpc/xprtrdma/rpc_rdma.c3
-rw-r--r--net/sunrpc/xprtrdma/xprt_rdma.h2
2 files changed, 3 insertions, 2 deletions
diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 7e9acd9361c5..91ffde82fa0c 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -738,8 +738,9 @@ rpcrdma_reply_handler(struct rpcrdma_rep *rep)
struct rpc_xprt *xprt = rep->rr_xprt;
struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
__be32 *iptr;
- int credits, rdmalen, status;
+ int rdmalen, status;
unsigned long cwnd;
+ u32 credits;
/* Check status. If bad, signal disconnect and return rep to pool */
if (rep->rr_len == ~0U) {
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index d1b70397c60f..0a16fb6f0885 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -285,7 +285,7 @@ rpcr_to_rdmar(struct rpc_rqst *rqst)
*/
struct rpcrdma_buffer {
spinlock_t rb_lock; /* protects indexes */
- int rb_max_requests;/* client max requests */
+ u32 rb_max_requests;/* client max requests */
struct list_head rb_mws; /* optional memory windows/fmrs/frmrs */
struct list_head rb_all;
int rb_send_index;