NL80211_ATTR_MAC was used to set both the specific BSSID to be scanned and the random MAC address to be used when privacy is enabled. When both the features are enabled, both the BSSID and the local MAC address were getting same value causing Probe Request frames to go with unintended DA. Hence, this has been fixed by using a different NL80211_ATTR_BSSID attribute to set the specific BSSID (which was the more recent addition in cfg80211) for a scan. Backwards compatibility with old userspace software is maintained to some extent by allowing NL80211_ATTR_MAC to be used to set the specific BSSID when scanning without enabling random MAC address use. Scanning with random source MAC address was introduced by commit ad2b26abc157 ("cfg80211: allow drivers to support random MAC addresses for scan") and the issue was introduced with the addition of the second user for the same attribute in commit 818965d39177 ("cfg80211: Allow a scan request for a specific BSSID").
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| @@ -323,7 +323,7 @@ · 322 unmodified lines | ||
| 323 | 323 | * @NL80211_CMD_GET_SCAN: get scan results |
| 324 | 324 | * @NL80211_CMD_TRIGGER_SCAN: trigger a new scan with the given parameters |
| 325 | 325 | * %NL80211_ATTR_TX_NO_CCK_RATE is used to decide whether to send the |
| 326 | − * probe requests at CCK rate or not. %NL80211_ATTR_MAC can be used to | |
| 326 | + * probe requests at CCK rate or not. %NL80211_ATTR_BSSID can be used to | |
| 327 | 327 | * specify a BSSID to scan for; if not included, the wildcard BSSID will |
| 328 | 328 | * be used. |
| 329 | 329 | * @NL80211_CMD_NEW_SCAN_RESULTS: scan notification (as a reply to |
| @@ -1977,6 +1977,9 @@ enum nl80211_commands { · 1647 unmodified lines | ||
| 1977 | 1977 | * @NL80211_ATTR_MULTICAST_TO_UNICAST_ENABLED: Indicates whether or not multicast |
| 1978 | 1978 | * packets should be send out as unicast to all stations (flag attribute). |
| 1979 | 1979 | * |
| 1980 | + * @NL80211_ATTR_BSSID: The BSSID of the AP. Note that %NL80211_ATTR_MAC is also | |
| 1981 | + * used in various commands/events for specifying the BSSID. | |
| 1982 | + * | |
| 1980 | 1983 | * @NUM_NL80211_ATTR: total number of nl80211_attrs available |
| 1981 | 1984 | * @NL80211_ATTR_MAX: highest attribute number currently defined |
| 1982 | 1985 | * @__NL80211_ATTR_AFTER_LAST: internal use |
| @@ -2381,6 +2384,8 @@ enum nl80211_attrs { · 398 unmodified lines | ||
| 2381 | 2384 | |
| 2382 | 2385 | NL80211_ATTR_MULTICAST_TO_UNICAST_ENABLED, |
| 2383 | 2386 | |
| 2387 | + NL80211_ATTR_BSSID, | |
| 2388 | + | |
| 2384 | 2389 | /* add attributes here, update the policy in nl80211.c */ |
| 2385 | 2390 | |
| 2386 | 2391 | __NL80211_ATTR_AFTER_LAST, |