cfg80211: scan: fix RCU in cfg80211_add_nontrans_list()
The SSID pointer is pointing to RCU protected data, so we
need to have it under rcu_read_lock() for the entire use.
Fix this.
Cc: stable@vger.kernel.org
Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning")
Link: https://lore.kernel.org/r/20210930131120.6ddfc603aa1d.I2137344c4e2426525b1a8e4ce5fca82f8ecbfe7e@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 11c68b1..adc0d14 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -418,14 +418,17 @@
}
ssid_len = ssid[1];
ssid = ssid + 2;
- rcu_read_unlock();
/* check if nontrans_bss is in the list */
list_for_each_entry(bss, &trans_bss->nontrans_list, nontrans_list) {
- if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len))
+ if (is_bss(bss, nontrans_bss->bssid, ssid, ssid_len)) {
+ rcu_read_unlock();
return 0;
+ }
}
+ rcu_read_unlock();
+
/* add to the list */
list_add_tail(&nontrans_bss->nontrans_list, &trans_bss->nontrans_list);
return 0;
