iwlwifi: mvm: properly check for transport data in dump

When copying from vmalloc'ed memory to the SG list, don't crash
if the transport didn't provide any data.

Fixes: 7e62a699aafb ("iwlwifi: mvm: use dev_coredumpsg()")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c
index e447cd92deb3db4d090704be0ff74cbf74e4bb05..e7b3b712d77833ee7ef079bbac9ec158e1afe90d 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw-dbg.c
@@ -848,11 +848,12 @@ dump_trans_data:
                                     sg_nents(sg_dump_data),
                                     fw_error_dump->op_mode_ptr,
                                     fw_error_dump->op_mode_len, 0);
-               sg_pcopy_from_buffer(sg_dump_data,
-                                    sg_nents(sg_dump_data),
-                                    fw_error_dump->trans_ptr->data,
-                                    fw_error_dump->trans_ptr->len,
-                                    fw_error_dump->op_mode_len);
+               if (fw_error_dump->trans_ptr)
+                       sg_pcopy_from_buffer(sg_dump_data,
+                                            sg_nents(sg_dump_data),
+                                            fw_error_dump->trans_ptr->data,
+                                            fw_error_dump->trans_ptr->len,
+                                            fw_error_dump->op_mode_len);
                dev_coredumpsg(mvm->trans->dev, sg_dump_data, file_len,
                               GFP_KERNEL);
        }