IB/mad: Fix an array index check

commit 2fe2f378dd45847d2643638c07a7658822087836 upstream.

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>
Reviewed-by: Hal Rosenstock <hal@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 2fe428b..78d406b 100644 (file)
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -1598,7 +1598,7 @@ find_mad_agent(struct ib_mad_port_private *port_priv,
                        if (!class)
                                goto out;
                        if (convert_mgmt_class(mad->mad_hdr.mgmt_class) >=
-                           IB_MGMT_MAX_METHODS)
+                           ARRAY_SIZE(class->method_table))
                                goto out;
                        method = class->method_table[convert_mgmt_class(
                                                        mad->mad_hdr.mgmt_class)];