From: Dan Carpenter <dan.carpenter@oracle.com>
To: eyal@wizery.com
Cc: Eyal Shapira <eyal@wizery.com>, linux-wireless@vger.kernel.org
Subject: re: iwlwifi: mvm: rs: refactor to allow direct rs updating
Date: Wed, 1 Oct 2014 17:55:53 +0300 [thread overview]
Message-ID: <20141001145553.GA32299@mwanda> (raw)
Hello Eyal Shapira,
This is a semi-automatic email about new static checker warnings.
The patch 1ebc8f2ef83d: "iwlwifi: mvm: rs: refactor to allow direct
rs updating" from Sep 14, 2014, leads to the following Smatch
complaint:
drivers/net/wireless/iwlwifi/mvm/rs.c:1228 iwl_mvm_rs_tx_status()
warn: variable dereferenced before check 'sta' (see line 1037)
drivers/net/wireless/iwlwifi/mvm/rs.c
1036 u8 reduced_txp = (uintptr_t)info->status.status_driver_data[0];
1037 struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Patch introduces a new unchecked "sta" dereference.
1038 struct iwl_lq_sta *lq_sta = &mvmsta->lq_sta;
1039
1040 /* Treat uninitialized rate scaling data same as non-existing. */
1041 if (!lq_sta) {
1042 IWL_DEBUG_RATE(mvm, "Station rate scaling not created yet.\n");
1043 return;
1044 } else if (!lq_sta->pers.drv) {
1045 IWL_DEBUG_RATE(mvm, "Rate scaling not initialized yet.\n");
1046 return;
1047 }
1048
[ snip ]
1223 /* The last TX rate is cached in lq_sta; it's set in if/else above */
1224 lq_sta->last_rate_n_flags = ucode_rate;
1225 IWL_DEBUG_RATE(mvm, "reduced txpower: %d\n", reduced_txp);
1226 done:
1227 /* See if there's a better rate or modulation mode to try. */
1228 if (sta && sta->supp_rates[info->band])
^^^
The existing code assumes "sta" can be NULL.
1229 rs_rate_scale_perform(mvm, sta, lq_sta, tid);
1230 }
regards,
dan carpenter
reply other threads:[~2014-10-01 14:56 UTC|newest]
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