[SCSI] libiscsi_tcp: fix max_r2t manipulation
Problem description from Xi Wang:
A large max_r2t could lead to integer overflow in subsequent call to
iscsi_tcp_r2tpool_alloc(), allocating a smaller buffer than expected
and leading to out-of-bounds write.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c
index d3ff9cd..e6e6aa9 100644
--- a/drivers/scsi/cxgbi/libcxgbi.c
+++ b/drivers/scsi/cxgbi/libcxgbi.c
@@ -2148,11 +2148,10 @@
enum iscsi_param param, char *buf, int buflen)
{
struct iscsi_conn *conn = cls_conn->dd_data;
- struct iscsi_session *session = conn->session;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct cxgbi_conn *cconn = tcp_conn->dd_data;
struct cxgbi_sock *csk = cconn->cep->csk;
- int value, err = 0;
+ int err;
log_debug(1 << CXGBI_DBG_ISCSI,
"cls_conn 0x%p, param %d, buf(%d) %s.\n",
@@ -2174,15 +2173,7 @@
conn->datadgst_en, 0);
break;
case ISCSI_PARAM_MAX_R2T:
- sscanf(buf, "%d", &value);
- if (value <= 0 || !is_power_of_2(value))
- return -EINVAL;
- if (session->max_r2t == value)
- break;
- iscsi_tcp_r2tpool_free(session);
- err = iscsi_set_param(cls_conn, param, buf, buflen);
- if (!err && iscsi_tcp_r2tpool_alloc(session))
- return -ENOMEM;
+ return iscsi_tcp_set_max_r2t(conn, buf);
case ISCSI_PARAM_MAX_RECV_DLENGTH:
err = iscsi_set_param(cls_conn, param, buf, buflen);
if (!err)