IB/mad: Fix an array index check

The array ib_mad_mgmt_class_table.method_table has MAX_MGMT_CLASS
(80) elements. Hence compare the array index with that value instead
of with IB_MGMT_MAX_METHODS (128). This patch avoids that Coverity
reports the following:

Overrunning array class->method_table of 80 8-byte elements at element index 127 (byte offset 1016) using index convert_mgmt_class(mad_hdr->mgmt_class) (which evaluates to 127).

Fixes: commit b7ab0b19a85f ("IB/mad: Verify mgmt class in received MADs")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index bc2a9c2caa3c0561f8e1f72f3996769afa25c201..d120f6ff1ea6be323902936fe734bc1e39f10833 100644 (file)
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1746,7 +1746,7 @@ find_mad_agent(struct ib_mad_port_private *port_priv,
                        if (!class)
                                goto out;
                        if (convert_mgmt_class(mad_hdr->mgmt_class) >=
-                           IB_MGMT_MAX_METHODS)
+                           ARRAY_SIZE(class->method_table))
                                goto out;
                        method = class->method_table[convert_mgmt_class(
                                                        mad_hdr->mgmt_class)];