5.4-stable review patch. If anyone has any objections, please let me know.
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From: En-Wei Wu en-wei.wu@canonical.com
[ Upstream commit b5d14b0c6716fad7f0c94ac6e1d6f60a49f985c7 ]
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 Link: https://patch.msgid.link/20240705023756.10954-1-en-wei.wu@canonical.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/virt_wifi.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wireless/virt_wifi.c b/drivers/net/wireless/virt_wifi.c index 4e906910f110b..be5201bd824c2 100644 --- a/drivers/net/wireless/virt_wifi.c +++ b/drivers/net/wireless/virt_wifi.c @@ -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;