#12197 NORM 13.1.0: xo-4 page faults and silent hangs on boot. mwifiex?

Zarro Boogs per Child bugtracker at laptop.org
Mon Jan 7 14:15:48 EST 2013

#12197: xo-4 page faults and silent hangs on boot.  mwifiex?
           Reporter:  pgf        |       Owner:  shep                             
               Type:  defect     |      Status:  new                              
           Priority:  normal     |   Milestone:  13.1.0                           
          Component:  wireless   |     Version:  Development build as of this date
         Resolution:             |    Keywords:                                   
        Next_action:  reproduce  |    Verified:  0                                
Deployment_affected:             |   Blockedby:                                   
           Blocking:             |  

Comment(by shep):

 Hmmm... very suspicious code in mwifiex_sta_init_cmd   where it allocates

         struct mwifiex_ds_11n_tx_cfg tx_cfg;

 on the stack and then later

         tx_cfg.tx_htcap = MWIFIEX_FW_DEF_HTTXCFG;
         ret = mwifiex_send_cmd_async(priv, HostCmd_CMD_11N_CFG,
                                      HostCmd_ACT_GEN_SET, 0, &tx_cfg);

 so the pointer to struct mwifiex_ds_11n_tx_cfg on the stack gets copied
 into the command and then when the command response comes back,
 mwifiex_process_sta_cmdresp (in a different kernel thread) calls

         case HostCmd_CMD_11N_CFG:
                 ret = mwifiex_ret_11n_cfg(resp, data_buf);

 int mwifiex_ret_11n_cfg(struct host_cmd_ds_command *resp,
                         struct mwifiex_ds_11n_tx_cfg *tx_cfg)
         struct host_cmd_ds_11n_cfg *htcfg = &resp->params.htcfg;

         if (tx_cfg) {
                 tx_cfg->tx_htcap = le16_to_cpu(htcfg->ht_tx_cap);
                 tx_cfg->tx_htinfo = le16_to_cpu(htcfg->ht_tx_info);
         return 0;


 I think this might be the stack corruption bug I've been looking for.  Now
 to try and verify this, and look around to see if there are other similar
 bugs nearby.   Oh, and of course, fix it.

Ticket URL: <http://dev.laptop.org/ticket/12197#comment:7>
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