@@ -136,6 +136,8 @@ static struct ieee80211_supported_band band_5ghz = {
/* Assigned at module init. Guaranteed locally-administered and unicast. */
static u8 fake_router_bssid[ETH_ALEN] __ro_after_init = {};
+#define VIRT_WIFI_SSID "VirtWifi"
+
static void virt_wifi_inform_bss(struct wiphy *wiphy)
{
u64 tsf = div_u64(ktime_get_boottime_ns(), 1000);
@@ -146,8 +148,8 @@ static void virt_wifi_inform_bss(struct wiphy *wiphy)
u8 ssid[8];
} __packed ssid = {
.tag = WLAN_EID_SSID,
- .len = 8,
- .ssid = "VirtWifi",
+ .len = strlen(VIRT_WIFI_SSID),
+ .ssid = VIRT_WIFI_SSID,
};
informed_bss = cfg80211_inform_bss(wiphy, &channel_5ghz,
@@ -213,6 +215,8 @@ struct virt_wifi_netdev_priv {
struct net_device *upperdev;
u32 tx_packets;
u32 tx_failed;
+ u32 connect_requested_ssid_len;
+ u8 connect_requested_ssid[IEEE80211_MAX_SSID_LEN];
u8 connect_requested_bss[ETH_ALEN];
bool is_up;
bool is_connected;
@@ -229,6 +233,12 @@ static int virt_wifi_connect(struct wiphy *wiphy, struct net_device *netdev,
if (priv->being_deleted || !priv->is_up)
return -EBUSY;
+ if (!sme->ssid)
+ return -EINVAL;
+
+ priv->connect_requested_ssid_len = sme->ssid_len;
+ memcpy(priv->connect_requested_ssid, sme->ssid, sme->ssid_len);
+
could_schedule = schedule_delayed_work(&priv->connect, HZ * 2);
if (!could_schedule)
return -EBUSY;
@@ -252,12 +262,15 @@ static void virt_wifi_connect_complete(struct work_struct *work)
container_of(work, struct virt_wifi_netdev_priv, connect.work);
u8 *requested_bss = priv->connect_requested_bss;
bool right_addr = ether_addr_equal(requested_bss, fake_router_bssid);
+ bool right_ssid = priv->connect_requested_ssid_len == strlen(VIRT_WIFI_SSID) &&
+ !memcmp(priv->connect_requested_ssid, VIRT_WIFI_SSID,
+ priv->connect_requested_ssid_len);
u16 status = WLAN_STATUS_SUCCESS;
if (is_zero_ether_addr(requested_bss))
requested_bss = NULL;
- if (!priv->is_up || (requested_bss && !right_addr))
+ if (!priv->is_up || (requested_bss && !right_addr) || !right_ssid)
status = WLAN_STATUS_UNSPECIFIED_FAILURE;
else
priv->is_connected = true;
When user issues a connection with a different SSID than the one virt_wifi has advertised, the __cfg80211_connect_result() will trigger the warning: WARN_ON(bss_not_found). The issue is because the connection code in virt_wifi does not check the SSID from user space (it only checks the BSSID), and virt_wifi will call cfg80211_connect_result() with WLAN_STATUS_SUCCESS even if the SSID is different from the one virt_wifi has advertised. Eventually cfg80211 won't be able to find the cfg80211_bss and generate the warning. Fixed it by checking the SSID (from user space) in the connection code. Fixes: c7cdba31ed8b ("mac80211-next: rtnetlink wifi simulation device") Reported-by: syzbot+d6eb9cee2885ec06f5e3@syzkaller.appspotmail.com Signed-off-by: En-Wei Wu <en-wei.wu@canonical.com> --- Changes in v2: - adjust coding style - remove unnecessary debug message --- drivers/net/wireless/virtual/virt_wifi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)