From: Johannes Berg johannes.berg@intel.com
commit a2083eeb119fb9307258baea9b7c243ca9a2e0b6 upstream.
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.I2137344c4e2426525b1a8... Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/wireless/scan.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -418,14 +418,17 @@ cfg80211_add_nontrans_list(struct cfg802 } 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;